1st post here... So please excuse any errors that might creep in.
I've also been speculating on moving from TS+ to TS HD+. I can't comment on the picture quality but I find just the PVR part worth it.
Have been using Tatasky+ for ~1.5 years. I think i took the plunge when espn/star went off hathway in the middle of the premier league season...
Been really happy with the PVR function of the box... I mainly use it to record the UEFA matches (airing at 12:15/01:15am) and watch them the next day. Also to record some of my fav shows (eg: man vs food

) in series link and catch up on the weekend. Well over time i've almost filled up the 160gb harddrive.
The TS HD+ i understand is 500gb.. so more to be recorded. Then there is HD for key sporting events... & I don't need to change the wiring from TS+... Win-Win all around
I do hope the response on the channel change is better thou.