After a week and a half, I'm still pretty happy with the Vibrant. It runs nice and smooth, the battery life is good (better than my N900, but it's a 1+ yr old battery and smaller). Although I do think Android handles low signal better than Maemo, as far as battery drain. Loving the bigger screen, particularly being amoled.

As I said before, my only complaints are lack of a kickstand (although if it really bugs me, there are cases that have kickstands built in), no FM transmitter (although I rarely used that). So, really, no real complaints.

I've found apps to replace just about everything on my N900 with the exception of truecrypt and a good nethack variant. On the plus side, I now have apps that weren't available for the N900, so probably more than a fair trade-off.

A couple of apps worth mentioning:

Astrid Tasks - Manage tasks, and gasp! syncs with Google Tasks. (free)
App List Backup - Just creates a list of installed apps, that you can use later to re-install, not a backup of the app itself, good for saving space, not data (free)

On the plus side, my S7 tablet just got flashed with the leaked version of Froyo for it. Much better experience with that now.

Amazon App Store: I wish there was a way to hide/delete previously purchased apps. I've got several of the free daily apps, and uninstalled them later. They still show up in the list. At some point, it will get quite unwieldy unless I can delete/hide apps. (Is anything similar available from Google?) I can see this being a problem a couple of devices down the line, as there may be apps you no longer need.

Weatherbug Elite has issues every couple of days on my Vibrant, and prompts to re-install. Also installed on my S7, so we'll see how that goes. Fairly annoying, particularly if I had actually paid for it. May be related to being from the Amazon App store, as it appears to work for a minute, crashes, and prompts to re-install from Amazon.

I'm quite happy with the Vibrant as my main phone. The S7 tablet is great for games, browsing, etc around the house (and out and about, although the Vibrant is fine for that as well. I might actually stop taking the S7 as many places. For more intense stuff, I have a laptop or desktop at home. This leaves my N900 somewhat orphaned, I haven't even picked it up in almost a week. So, now I'm left to decided what to do with the N900. As much as I love it, it may just have to go up for sale.