I already have z4root for the Wifi Tether (which I only occasionally use). So the annoyance of running z4Root first is not an issue.
I have searched many "Top 10 Reasons to Root Android" and most include some of the HTC Apps not available to other Android phones.
If I needed Full Root to get Wifi Tether I would have by now.
A few reasons I have not rooted that I'm not sure of are:
1) Seen a lot of threads "X don't work after I Rooted/Installed ROM X". I admit I didn't read them in detail.
2) There are lots of warnings about backing up RSA Key's before rooting. But the "Unrevoked" method does make it clear that, that is done for you or not.
3) Updates from Sprint won't work without UnRoot and ReRoot. Not sure how big a deal that is.
My battery is running just fine. Space is fine, I have not even checked
If rooting could fix any of these:
1) the Android Browser to zoom text colums correctly.
2) Fix Navigating to Contact Address through Voice Search.
3) Fix ANY improvement Voice Search (like confirmation) I'd do it in a heart beat.
4) Improve Portrait Keyboard. With the HTC Keyboard in Portrait Mode (I'd rather pull out a stylus) than to type as many mistakes as I do. Works in landscape but I can't stand it taking up 4/5ths of the screen. The Stock Android Keyboard looks worse. I can see why so many folks want physical key boards. I always used my stylus on the TP2. Slow but very few mistakes. So if rooting can help solve that I'm in.
I don't watch movies, do facebook, Tweek or play games. Phone, Exchange, Contacts, Nav, VoiceCommand, WIFI Tether are my most critical needs.
What will Rooting buy me?
Thanks