While I personally prefer the grid guide there is no reason not to have a choice.
Regarding the live guide, in 21.8.1.RC6 the mini guide (up arrow I think) has become a decent replacement for the live guide. It does not show as many hours of the channel at one time but it is close.I have nobody to blame but myself. I read the warnings about Live Guide being gone, and losing my recordings if I wanted to roll back. I'm just a sucker for new and improved, and I figured "hey, it's TiVo. They'll get it right".
I've been Tivo'ing since DirecTiVo. Prior to that we had Microsoft TV, which was not bad but not TiVo. I briefly switched to U-Verse for the Total Home DVR (and HD), it was okay but not TiVo. I looked at the Comcast DVR when we dumped U-Verse but the menuing and guide were horrible. Back to TiVo (Roamio OTA), and happy again ... until now.
I've been a devoted TiVo fan for 15 years or more, but pulling the Live Guide in order to mimic the horrible UI on competition that TiVo had trounced was just beyond stupid.
I have 2 TV's, one with Roamio and a Roku, the other is Roku TV with TiVo mini attached. I used to go to the TiVo first, but since Hydra, I'm leaning more toward apps on the Roku.
If they don't fix the guide soon, this will be the last TiVo I buy. They're no longer better than anything else on the market.
Oh BTW, what's the deal with preserving recordings going up, but erasing everything if you come back down?