It's not that those features were over looked. TiVo as it is in the USA is what we have with a few changes and there are lot more to come. It went through testing for months before being released, and as long as the basic TiVo features worked then I assume it was ok to release. All the other additions and changes will take a while to implant and you wouldn't want the TiVo to not be released till all that was sorted out do you?
I've been using mine for a long time and would not go back to the V+ at all. TiVo is just much better and I am happy to deal with the few issues, I never used reminders on V+ nor did I ever use the red button, so for me there isn't anything missing
Neither does my TiVo slow down at all, nor do I have any problems with PQ on my Samsung 46" LCD TV.