Having played 4E for several years now, there's a lot of formatting in the document that just feels annoying, but which I probably have to just get used to again. The prose spell descriptions for one. Here are some other red flags that I noticed upon a single read-thru that turn my nose up a little, but which might not be as bad as they seem on initial sniff:
The weapon table. And having "duplicate weapon effects" with such disparate costs.
The fact that you have a Club, Hammer, and Mace all do 1d6 bludgeoning damage except the Mace costs 6 gp and weighs 8 lbs and the club costs 5 sp and weights 3 lbs makes me wonder why anyone would use a Mace? Had there been a special property to make the Mace worth more than the Club, then fine (like the Hammer is Light and can be thrown). But right now, there's no point of having the Mace. Same thing with the Pick and Trident-- same damage, except one costs 8 gp and the other 15 gp. Which makes one of the two pointless.
Perhaps there are more advanced rules that will actually give something to these 'less than' weapons... but at the basic level, it just rubs me the wrong way.
I'm also not crazy about the insane jumps in price on the armor table either. The fact that fighters were supposed to be the most heavily armored, and yet a rogue with a +3 dex mod can get a 17 AC for 75 gp while a fighter with no dex mod has to spend 1,500 gp for the same AC? That's insane. Or the fact that Studded Leather gives you 13 + dex for 25 gp, but Ringmail gives you 13 + half dex for 35 gp? So basically you're spending 10 extra gold for armor that only half as much dex bonus.
It's these kind of illogical things that I was so glad they eliminated (for the most part) in 4E, that I will really hate to go back to. Because they make absolutely no sense and basically remove certain armors and weapons from ever being taken because there are better options available at every turn.