On experience and levelling
I ran a 2e campaign from 10/96 to 10/00, when 3e came out. Over that period we probably played 3 sessions per month, on average - so I guess about 100 sessions. The characters rose from 1st level to 9th in that time. Levels 1-4 were fairly rapid, 5-7 quite a bit longer, and 8-9 was just tedious. The last two adventures I ran in that campaign were huge mega-adventures, taking 3-4 months of real time, i.e. 10+ sessions, or 40+ hours of playing. I tried to hand out xp like it was confetti - I gave the party (of five) mission bonuses of 50,000xp or 100,000xp. Conclusion: 2e experience at mid- to high-levels was way too high.
I ran a 3e campaign from 10/00 to 10/02. Characters went from 1st to 9th level in that time, about 60 sessions. If I'd given out standard xp, the characters would've been about 11th level. Not too much of a problem, just slightly faster than I would've liked as DM. Hence, I artificially held characters at lower levels. Seemed to work OK.
I started running another 3e campaign just this year. We've played 6 sessions (say, 24 hours), and characters are on the brink of 3rd level. I have no problem with characters rushing through low levels - as a DM, I find mid-level adventures most fun, so I like to get my characters there quickly, then keep 'em there! Consequently, I have modified the standard experience tables.
Everyone knows that for each additional level, the character needs to earn 1000xp more than he earned for the previous level (i.e. difference between 1st and 2nd level is 1000xp, difference between 2nd and 3rd level is 2000xp, difference between 3rd and 4th level is 3000xp, etc.). To slow progression down at mid- and high-levels, I've proposed that each level from 6th-10th level requires 2000xp more than the previous level, each level from 11th-15th level requires 3000xp more than the previous level, and each level from 16th-20th level requires 4000xp more. Of course, this is a work-in-progress - I have no idea how it will work in practice, as the PCs are only 2nd level.
On treasure and magic: I've always been a stingy DM, and over many years the players have come to accept that. In 3e, I'm a little freer with magic that I used to be, but not much. For example, in the previous campaign, the 9th level cleric of Heironeous had a +1 longsword (no special abilities) and had only just been given a suit of full plate armour by his church as a reward for services rendered prior to the last adventure. The fighter/cleric of St Cuthbert had a +1 heavy mace, bane vs evil outsiders, masterwork half-plate, and a heavy warhorse from the stables of the region's Duke (it had higher Con than standard). The Ftr3/Wiz6 had a +1 mighty (+1) shortbow, +1 mithral chainmail and a pearl of power (1st level) taken from a drow she had killed. The Mnk9 had some bracers which imbued him with magic fang once per day (for 10 rounds only) and some slippers of the tiger's leap (double unarmed damage in a charge). These are 9th level characters with what some would regard as pretty crappy magic for their level. But the point is that it worked well in my campaign. The good stuff the characters get (with the exception of scrolls and potions they might make themselves) are those they take off the bad guys - which frequently are either useless to them or are downright dangerous to keep - or are those they are given by grateful people in power.
I haven't yet permitted PCs to take magic item creation feats other than Brew Potion, Craft Wand and Scribe Scroll. In the immediate past campaign, I required Spellcraft checks to manufacture even those one-shot magic items (DC = 15 + spell level), and if the Spellcraft check failed, the cost, time and experience needed to create the item was wasted. In this campaign, I won't have PCs wasting their money and xp, I'll just say "given your other tasks, in the time you have, you can only scribe 3 scrolls", for example.
At the end of the day, experience, treasure and magic items are all within the control of the DM. The DM needs to set some ground rules to ensure that players don't feel cheated out of what they think is rightfully theirs; fortunately, I've been playing with the same crew so long that they're resigned to my stinginess...
Cheers, Al'Kelhar