Exploring e-Tools is an adventure in of itself. At first, you think "I'm not sure this is going to be useful to me". Then as you work with it, and find out that "Whoa! It takes care of this! And that!", you start finding that it's extremely useful. I was also strangely surprised to find that the component that I've used for actual play the most is the treasure generator/editor.
I was writing the "next section" of the complex I was working on for the upcoming play session, I didn't care what the treasure was, and it was all stuffed in one location. So I hopped in the treasure generator, typed in the EL of the first encoutner, checked the append box, and voila! A list of treasure randomly generated. Then, I do the rest of the encounters, and get a nice random list. But of course, I wasn't satisfied with the list (I've never been happy with most random lists). So I clicked on the "jump to treasure editor" button, and removed some bits, added a "Heward's Haversack" which I particularly wanted, changed the money a bit...and then went to "stat block" and cut and pasted the results into my MS-Word document. I could have saved to file, but I didn't see the need.
Then gave the character editor a real try (having previously just "messed around" in it). I sat down to enter my 9th level dwarven cleric in it. It was frighteningly easy. At one point, I thought I was going to run into trouble, I had some loot he carries that definitely wasn't in the books (a statue he made, for example). However, it took me all of a minute to hop over to the house rules editor, enter the items, and then hop back to the character editor and add the equipment (I've seen comments that you need to leave e-tools after making changes. That's not strictly true...many things "update" if you move away from the list and back). Same routine when I got to the spells...I use a few spells from Defenders of the Faith, it was not difficult at all to add those spells on the fly, as it were. In the end, I got everything entered, spells, statues, etc...in just 40 minutes.
Printing proved to be painful for me. As it turns out, the inkjet printer I was using wouldn't set the margins small enough (because of it's required "grip" space) for the character sheet that comes with the product. I could almost get everything to fit correctly on a page, but the last line of the box for languages ended up on it's own page.

. At some point, I'll sit down and design my own character sheet (I rarely like default formats anyway, so the ability the design my own is probably more important than the default one printing corrrectly on my printer!)
The tool that I feel isn't getting the attention it deserves is the "table editor". Admittedly, it wasn't as immediately intuitive how to use, but once I figured out what to do, being able to make my own "random tables" and then go to the generator and immediately use those tables was very useful!
The Creature/Race/Monster editing is very easy to use...but, there are definitely some things there I don't like: No way to change the "base type", "subtype", and hit dice after you start editing is probably my biggest peeve right now. My other peeve is the lack of "detail" with some of the special abilites. I'd like to see instead of just Damage Reduction (Ex), the whole info: Damage Reduction (15/+1) (Ex), and the like. The lack of detail puts the race/monster editor in the useful, but not all the way there category.
Unfortunately, as we all were informed FROM DAY ONE, e-Tools contains only the information from the Core Books. To be honest, I can't see a reason to complain about it, though...it takes alot of people-hours to enter data, double-check that it's correct, deal with weirdnesses...trust me on this one. When extending the tool I currently (or used to use, now that e-tools is here), nothing was more painful than adding some of the class-books, things from dragon magazines, etc. You have to narrow your scope somehow, and drawing a line at the Core Books to start with is a good place to do so.
I've seen many complaints about it not doing X, or not including Y, and so on. Many of those complaints appear to be user error rather than actual problems with the program. Either the user doesn't actually understand the D&D rules or they've failed to realize how the program works.
Unfortunately, one of the complaints is a result of what I think was the "wrong way" to make the interface: User entry of the "abilities". Personally, I'd like the interface to simply allow me to enter the actual score I have. Instead, it operates on a "base of 8 plus a change" method, which has confused alot of people.
On the flipside, people are griping alot about "a basic item like a +1 longsword isn't in there! Why do I have to create it first?" First of all, a +1 item isn't "basic". It may seem simple to you (although it shouldn't...but that's a entirely different issue!

, but it's not simple technically. The program have a few options here. The first, they could sit down and enter every weapon, and then add every weapon again with +1, and every weapon with +2...heck, you could even have it do that automatically. The result would be blooming ridiculous, however. You'd end up with a weapon list that was incredibly long. Perhaps instead we could have a "prompted" input for the pluses? Not a bad idea...except what do you do about special abilities (flaming, shock burst, etc.) as well? Darnit! I want my +3 flaming throwing daggers! So you add yet another prompt (I'm assuming you don't want every variation of that as well on the main list...

for special abilites. And we've not even gotten to "intelligent" or "cursed" items. How many prompts do we add? Or how many list items do we add? (Anyone have a calculator handy? It'd be interesting to work out how many different combinations there really are! Pluses alone it's N*5 (N=number of weapons)).
What they did instead makes sense. Not necessarily the way I would have done it, but it works, it covers the basis, and if you want to make a +3 flaming vorpal intelligent cursed item...you can. You can even do it with weapons that you normally wouldn't think anyone would want, but the possibility is there...and eventually, someone will want it, probably me, since I like to break archetypes by playing characters that like to use atypical weapons, or choose unusual spell sets, etc.
There /are/ bugs, there /are/ some things that should be there that aren't. Most of them, though are minor, and what I would expect from a product that has to deal with as much detail as this one does. Stop and think about it...sure, monster #346's skill checks are wrong by +4, because someone forgot to add the racial bonus, but come on, when you consider how many tiny details make up those skills, you should regard it as a miracle that all the data is as close as it is now! (the voice of painful experience again)
Overall, I think it's a great product...has a huge amount of potential uses, and for $29.99, is probably more reasonably priced pieces of software. I was expecting to have to pay $50, and was pleased to have gotten it for $30.