Summary: If you don't have a LOT of tasks and a LOT of calendar items, you'll probably never experience the problems I've had.
After nearly two weeks of frustration and delay, I had a technically working phone, but it was unusable. Trying to look at my calendar, or tasks, or email, was an exercise in patience. Actually, it was working, as long as you didn't mind things taking a minute or two to respond.
This icon shows up a lot when Windows Mobile is busy. In general, it's animated. Except when your mobile device is so consumed that it can't even paint the waiting icon!
It's funny, but something about this seemed familiar. Then I remembered...Outlook had some issues like this for people who have a lot of tasks and calendar items, especially recurring items, and even more so if a lot of those items had reminders on them. I *live* in Outlook, and yes, I do have lots of tasks and calendar items, and yes, many of them are recurring, and lots have reminders. Perhaps the mobile device has inherited these issues from it's PC ancestor?
After lots of pruning of tasks that really don't need to be on my mobile device (sure wish there were more controls on synching), I got the number down to something much more manageable. (under 200 active tasks) Synched again, and now things are seeming a bit more reasonable. Not exactly zippy, but certainly tolerable. When a call comes in, I can actually answer it! When new email arrives, I can read it. OK, now we're getting somewhere.
Well, here I am 3 days later and I'm beginning to get happy with this device. It's doing what it was intended to do. I can check my calendar, I can work my tasks, I can tell when I have new email, and in most cases, I can respond to that email from just about anywhere. I occasionally bump an unintended button while pulling it out of the holster, but that's just a learning process for me.
So...now it's on to more fun stuff. Really tweaking this thing to fit my needs. Next week will be the real test as I'm traveling all week, living off the mobile device rather than my notebook. Can I do it? We shall see...

Okay Tony...glad it's working, and full speed ahead for me! I just ordered the 8125, it should be here next Tuesday. I decided to go for the non-refurb just in case. Now we'll se what happens on my end...
Posted by: Matt Singley | September 15, 2006 at 04:31 PM
Tony,
Check out the xda-developers forums for some tips on this phone. They even have some pretty decent firmware you can flash it with that really helps the speed. You'll need to re-install and re-sync everything, but the updated firmware to this phone is a must. Cingular has an official update that's just a little behind what's available by the people who "cook" their own ROM upgrades - either way is well worth the trouble.
-Pete
Posted by: Peter Schott | September 18, 2006 at 04:48 PM
Hey Tony, did you try the route that Peter suggested above? I'm fully operational with my 8125 now, just curious how this works...
Posted by: Matt Singley | September 28, 2006 at 10:41 PM
Actually, after cleaning up my tasks, calendar, and contacts, I've resolved the major issues and am pretty happy with how the 8125 works. I'm sure I'll do some future adjustments, but probably not terribly soon. I'm trying to stay "factory standard" to help me support our other 8125 users.
Posted by: Tony Dye | September 29, 2006 at 04:02 PM
Can I ask Tony how things are faring with your use of the 8125? Are you doing anything different (better or worse) because of the 8125 now?
And what neat software are you using (ChMS even, hehehe)?
Posted by: Antoine of MMM | October 25, 2006 at 10:50 AM
My 8125 has been doing fairly well. The key was to trim down the number of tasks, appointments, and contacts I carry. For instance, by getting rid of a lot of my completed tasks, performance improved considerably. I'm still trying to trim down my contacts -- it's very slow searching through the 3000+ that I currently have :-(
As to ChMS, consider: anything that synchs with Outlook becomes a candidate. 'nuf said?
Posted by: Tony Dye | October 26, 2006 at 12:04 PM