Sprite does a soft reset on your phone before it starts a backup, no it doesn't wipe your phone, just a normal soft reset. I'm guessing it does this just to make sure there are no programs running that can screw up the backup..
I too can attest to how well Sprite works. I've been using it since version 3 and I must say that version 6 works GREAT with the Tytn/Kaiser/Tilt. I by mistake half installed the MS Framework services (Don't do that!!
) and had to restore from backup which worked perfectly!
Now I'm not sure if this is a function of Sprite, or ActiveSync, but once you restore with this version you won't have to fully sync again which saves you from getting duplicate contacts,calendar events. With the older version you'd always need to do a full sync and ran into the issue with duplicate info..