I like Leona but you're right she's a bit dull. She has the voice but nothing else, which is a shame because she is one of the best singers we have today.
Alexandra is full of fire and is clearly the R'N'B/Dance act to even out against Leona's ballads. Two totally different X Factor winners is good for the show.
JLS however have the POTENTIAL but if they're going to have more songs like Everybody In Love then they're just going to be another cheesy boyband.
I do think Ruth Lorenzo and Diana Vickers will be the ones to watch, though.