Xilo seems like a decent package.
All that i require it seems and includes line rental at £26.54 on the Talk Surf Pro 50Gb.
I have been on Xilo Talk Surf 50 for over a year. The connection has been stable almost all of the time. Support has been second to none when I had internal wiring problems.
Cost of phone calls is also very inexpensive compared to others. I do not have Pro and to be honest, I don't see any need for it and talk surf is a few pounds cheaper.
Prior to moving to LLU, my sync speeds were all over the place due to frequent re-syncs and BT profiling. It is now a rare occurence for my modem to re-sync.
On Xilo/TalkTalk LLU, the ISP can manually set the target SNR and if your line is stable this can give you an increase in sync speed.
The only possible problem could be if at some time you want to return to a BT line.