I wouldn't align any technical capability with the problems people had. I suspect that the problem was just lack of robustness in the design, so a certain percentage of circumstances simply won't work, no matter what, while the vast majority will work, with comparatively little effort or technical know-how applied. So my recommendation is to buy the TiVo Series 3, being sure to pave the way for your merchandise return. (Make sure that you have a money-back guarantee that covers not being able to get it to work well-enough, that there isn't a restocking fee, that it won't cost you a lot in shipping to return it, etc. and make sure that you're prepared to return it if you cannot get it to work in the alloted time before your money-back guarantee runs out.)
I cannot help you with DirecTV. All the options available are available through DirecTV only -- they have closed their systems to independent consumer electronics.