The stock Froyo messaging is definitely nothing to write home about when compared to BB.
However, you should try either MailDroid or K-9 Mail (available on the market for free, though MailDroid does offer an ad-free version, but it's expensive). They both offer approximately equivalent functionality, so for many the choice boils down to what works in their environment and which user interface works best.
I've been using MailDroid since about August and like it. The devs for both programs appear to be pretty responsive. I can vouch for the MailDroid dev as I've had a couple problems he's addressed pretty quickly. Try to find that kind of service with RIM!
Welcome to the world of Droid X. I'm looking forward to the DX2 when it gets here later this year, but I have to admit that I LOVE my DX!
Oh, for those of you who were willing to try different, unofficial VZW versions of the BBOS, I think that rooting your DX is well worth the effort and just adds another level of "wow!" to the equation.
BTW, don't forget to try the Swype keyboard (Settings, Language and Keyboard, Input Method, Swype)! There are many videos on YouTube to get an idea what it will do. Also, there are other good keyboards available including: SlideIt (very much like Swype, but arguably learns better and is a ~$6 pay app), SwiftKey (a very good learning keyboard for "thumbers" and is on sale @ 60% off, $2), and others. Almost all have a free/trial version available with differing limitations (if any). This is one of my favorite Android features.
Also, you really need to get an app like Juice Defender to extend your battery life. I'm not saying that JD is "the one to get", but rather that there are apps available that will significantly increase your battery life and only with slight drawbacks. Again, free/trial versions are available of all.
For those of you who root your DX, you can also try an over/underclocking app such as SetCPU, Droid Overclock, etc. Droid Overclock (DO) for one, also allows you to undervolt your CPU, extending the battery life even more without hampering usability. The only drawback I've found to DO is that when you change the clocking, you either have to drop the top speed (say 1000Mhz to 900Mhz) to keep the same "lowest" speed or if you keep the same or higher top speed, your bottom lowest speed will be raised, sometimes fairly dramatically.
I'd also suggest you check out some Calendar extensions such as CalenGoo (also has an iPhone version), Pimlico, Jorte, Calendar Snooze, Simple Calendar Widget (simple, free, "Agenda/Today" view), etc. Any of these (and many others) will make the Android/Google calendar much more useful.
Unfortunately, CalenGoo and Pimlico do not have free/trial versions. This is unfortunate because I believe them to be the most functional of the calendar extensions and think they would get MANY more registrations if they did offer free/trial versions.
IMO, stupidly, Google dropped the app refund time down from 24 hours (barely enough to adequately test a complicated app like a calendar extension) to a ridiculous 15 minutes, a totally inadequate time period.
Personally, I'm using Calengoo and I'm very happy with it.
Get a barcode scanning app such as ShopSavvy or Google Goggles (and others) for scanning product barcodes to look for better prices and/or just to be able to scan the increasingly popular QR Codes you may have noticed. Way cool stuff!
Another app is AdjBrightness, which can drop the system's brightness down to 2 (1 to 255 range), which is great for reading in bed to avoid irritating your significant other.
Oh, how could I forget?!? The Kindle and Nook apps are musts and, now that B&N has provided a recent update, the Nook app is rather exceptional and has more utility. However, both allow you to tap into your existing books and read them on the DX's rather large screen. NICE!
One final app I'd recommend is Widgetsoid. It gives you a convenient way to toggle various settings without having to dig through the Settings menus.
Other apps/app categories to try (in no particular order or explanation):
1. Other media players like WinAmp, mVideoPlayer, Rockplayer, TuneIn
2. Other browsers such as Dolphin HD, Opera Mini 5.x, Skyfire.
3. Various voice recorders
4. File managers such as Astro, Root Explorer, Ghost Commander
5. Easy Tether, Network Info II, Lookator, etc.
6. GAMES! Angry Birds, Abduction, Bejeweled 2, Blow Up, Hyper Jump, Doodle Jump, Hungry Shark, Pocket God, Super Tumble, Space Physics, The Sims 3, Toss It, X Construction, and HUNDREDS of others! Worth it just to keep the kids quiet on trips!
7. Text messaging such as Handcent SMS and other excellent programs.
8. Different "Home Launcher" programs such as Launcher Pro, ADW, Go Launcher, etc.
9. Androidify
10. Anti-Virus such as LookOut, Trend Micro, others.
11. Weather apps such as Go Weather (my favorite), Weatherbug (requires tracking you via GPS), Accuweather.com (no widget), The Weather Channel (requires tracking you via GPS), and others.
12. Tapatalk, gReader, etc.
13. I'm not a social networking person, but there are many FaceBook, Twitter, etc. apps available which are reputed to be quite good.
14. *GOOGLE* VOICE SEARCH WITH VOICE ACTIONS (not Pannous Voice Actions)! You really need to check out the ~20 minute official Google video on Voice Actions on YouTube to really appreciate how AWESOME this is, especially compared to ANYTHING that RIM can/might do!
15. Don't pay for VZ Navigator anymore, use the free and IMO better Google Navigation (in combination with Google Voice Search)!
Hope these help! They have definitely made my life easier.
Oh, I did some travelling recently and got a newfound appreciation for my DX. I had Google Navigation, Trapster, and TuneIn all running at the same time I was getting my favorite (home/local) radio station music (TuneIn), Police/camera location reports (Trapster, you know, in case I needed their help or wanted to wave at the cameras), and step-by-step directions, with up to date traffic info (Google Navigation). My old S1 would have trouble keeping up with any ONE of these, much less all three together... and that is with the DX underclocked to 900Mhz.
Scott