I picked my Hero up from Best Buy last week (I also really recommend going through Best Buy to avoid waiting on the $100 Sprint rebate). It's been a week now and I will say one thing about the Hero... it's complicated. That's not necessarily bad, but you WILL need to read the instruction book for this phone. My last phone was ancient with bare features, but I'm pretty gadget intuitive and this thing has a million settings and getting to them doesn't always make the most sense. You will also need to become familiar with the HTC website help section!
The Android market is pretty vast and they have a lot of free apps, but it's no easier to search than the Apple app store. It will list things by category, then by popularity or date - but the sorting options, as in the Apple App store, are pitiful. Android market also has a few "featured" apps listed at the top, and the catalog does give star ratings and lets you see reviews but there are no screenshots at this point - which until they weren't there, I didn't realize how useful they are! Annoyingly, to delete an app from your phone, you have to go into the Market and view your downloads and uninstall them from there.
Lag...it's minimal, but is there. Again, I don't know that you would notice it unless you were used to using the iPhone/iPod Touch. The keyboard is pretty responsive - but not quite as good as the iPhone. Make sure you calibrate the keyboard because that does help. I have an iPod Touch and my boyfriend has the iPhone, so I am more used to using those devices. If you haven't used those, I don't think you'll notice the keyboard being off at all. But I'd compare it to playing PS2 games on the PS3 - they work, and work well, but it's just a little off.
The camera is pretty good and I think it's better than the one on the iPhone, but it's not stellar by any means. It has a few effects (grayscale, negative, sepia) and you can download other effects for free off the Marketplace.
Battery life...Sucks, but my old phone was a horse in that department. I can get through a day - barely - and that's with suggested modifications made (like turning off wifi, limiting facebook updates and twitter updates, turning off the vibrate mode for the keyboard response - which can be a nice feature to have on, btw). I turn the phone on for an average of 10 minutes every hour and make almost no calls and the battery is below 20% by the time I get off work. I think most phones of this type suffer with battery time though and I would say it's a little worse than the iPhone but maybe there are still a few more settings I can switch off. The battery does seem to charge up pretty quickly.
Small annoyances... The alarm feature is decent BUT the snooze indicator is miniscule and doesn't register being touched most of the time. (I always use my phone as my alarm so this is really annoying to me but probably not to most people!) You have to turn the phone on and unlock it (assuming you have lock set) to be able to change the ringer volume. You cannot have it on the loudest ringer setting with vibrate, as my last phone allowed. And the vibrate itself is a joke and can barely be felt, even in my girl jean pockets.

As far as I can tell, HTC sync is Windows only. You don't unlock with a number code, but by a "pattern," which I understand is the Android norm.
Nice touches... the teflon backing is nice to the feel. The trackball is nice, though I really worry about its ability to withstand 2 years of use without failure. It has visual voicemail. You can do a google search by voice. Sprint TV is a nice bonus. The contacts ("people") are well arranged and by looking at a contact, you can also see a list of all your emails, phone calls, and texts with that person. There is also a nice "send directly to voicemail" option. Now, if only I had someone I didn't like who called me that I could use that on.
So overall, honestly, I'm undecided. I do prefer a physical keyboard, so the Samsung Moment might be more up my alley, but I think the screen is smaller. I've been with Sprint since 2000 and I've never had any problems with them, and I get a great plan due to having a 20% discount. I would switch to the iPhone in a heartbeat if it was on Sprint, but I hate AT&T and their massive amounts of dropped calls and their overpriced calling plans. The Hero is a good phone, but most of the reviews I've read (and I've read many) seem a little overly glowing.
Oh, and no Cooking Mama. You can see what there is in the Market by searching online:
http://www.android.com/market/ There are some screenshots on the website, but not in the actual Market that you see on the phone. And I haven't really used the radio apps yet.
Now I know the CAG iPhone app is almost ready... I just wonder if there is going to be an Android app too?