The interface is a matter of taste; many Roku users prefer its interface. I've heard TiVo and even PS3 users curse it (Westly-C says he hates it--as compared to this older UI whose browser was more powerful--back in this post). As mailiang points out, your problem with the Roku's Netflix player performance is a personal one. My Roku 3 is definitely one of the highest performers of the several platforms I have, including the PS3. It starts the player from the home menu in 4 seconds and streams in 1-3 seconds. In its favor, recent versions of the PS3 ramp up to the higher bit rate video encodes much faster, it has the (undocumented, unsupported) stream info display and I probably prefer the PS3's UI. I do not use the PS3 because my launch model draws somewhere between 170-180W while streaming video versus the Roku's 3.5W and no more than 11W or so for a BD player. The PS3 also has a noisy fan which kicks in after about 15 minutes.
Edited by michaeltscott - 5/13/13 at 1:49pm