There is that route - I carry my 6800 even though I have a Touch Pro. If something happens to my Mogul, I can get that replaced with whatever down the road. I hit my 2-year upgrade eligibility in April and with the new phones coming soon, I am in no hurry to move to anything else just yet.
I love my Mogul - it's tougher, has more buttons (which I use regularly) and lasts longer doing the daily things I enjoy using it for. I browse forums, tether via wifi, I have EAS active constantly. GPS is used pretty often with Googlemaps or Live Search (
there's a new version out BTW if you weren't aware) too. I, for one, am really happy with this phone.