[quote name='mtxbass1']Huge differences IMO.
I play both regularly.
Singstar has about 880 songs total. They have a huge backlog of PS2 discs that you can play on the PS3 versions. It shows the video while you're singing, although they really look like crap. Most videos are based on the original feed and are pretty rough looking. Singstar has support for recording a performance and putting a portion of it online. It also has the usual sing solo, battle modes, etc.
Lips IMO trumps singstar in the fact that it has WIRELESS mics. I think the UI is worse when trying to find a song, but I enjoy Lips more. The songs sound better. The videos look better. The different play modes are better. If Lips had more songs there would be no reason to even pick up Singstar again.[/QUOTE]
Another positive of Lips over Singstar is the "rap" songs. In singstar, it is close to impossible to get a decent score for them since it doesn't seem to register for anyone (check the singstar forums). In Lips, you can actually do well on them since it just checks that you make a noise on each word/phrase. Granted like said above, Singstar has a way better interface.
Question about the I love 80s disc... does it pick up your US downloaded tracks or would I have to swap out of the disc to a US disc in order to play them?