As one who had a Pre before a Hero, I would ask if you value text messaging and instant messaging? If you value either of the two, go with the Pre. After a few months of using the Hero, I have about 5000 text messages. The biggest thread has 1560 messages. It took me 3 minutes and 35 seconds to open that one thread. The texting is so worthless that I switched back to my Centro! My Centro has 20k+ texts, and all threads open instantly. The Pre's messaging is great (tho still not Centro fast) and I truly miss the all in one nature of the chat logs (all sms, google chat, yahoo, aim, etc from one person ends up in the same thread). If you're not a texter or an instant messenger, and you value navigation and web browsing, then consider the Hero. It honestly rocks at the two. The Pre is no slouch at web browsing, but its browser just isn't quite as good as the Hero's. Sprint Nav (Pre and Hero) <<< Google Nav (Hero), but it is functional, and will get you there. The Pre has slightly better reception (especially if you slide the keyboard down) and roughly 30% better battery life in fringe reception areas, and turning on wifi will actually improve the battery (and doesn't slow the phone down). The Hero has ~ 30% better battery life in good reception areas, but turning on wifi slows the phone down and eats the battery. Neither one of them has force roaming like the Centro, and they both have bad reception and bad battery life compared to the Centro.
Pre's hardware is honestly not any worse than the Hero. I'm on my 4th Hero in as many months. My first Pre worked fine for 6 months. I think that HTC's "quality" is a myth, I would compare it to a 1999 VW Jetta. It looked and felt better on the inside than any other car in the sub $60k price bracket, but they generally didn't hold up very well. The Pre just kinda feels loosey goosey from the get-go, but as long as one can refrain from dropping it on the power button and won't charge it with a 50 cent Big Lots car charger, it will probably hold up fairly well. The most frequent problem is the phone gets dropped on the power button in the corner which messes it up and you gotta be careful when pulling aux. plugs and headphone plugs out (same as with Centro) or sometimes the phone thinks the headphones are still plugged in.
I am trying to not endorse or knock either phone too much, but I'm pretty unhappy with my Hero --- but if you're not much of a texter then you'll probably be happy with the Hero.