luki,
I have an X1 as well and I have recorded some church hymns for my grandfather (he is a Pastor and wanted some music tapes done for playback) I did him some hymns using the styles recorded via the sequencer and I was even amazed at the results myself !!..
I would disagree with you with regards to the I30's styles, I used to own one too and I thought the styles on it were excellent, especially the Dance stuff.. I am sorry but the PSR740's styles DO NOT compare to the I30's (even though the 740 has some good styles i think they are in a different league). I agree though with the sounds on the I30 are weak, this was the main reason for selling it as well poor user interface and (i hated the touch screen) and the lack of amplification (in a church scenario i think a keyboard with an AMP built in is essential). I have used the PSR620 in church before (many moons ago when I was a regular goer) and i hated it when lugging the extra amps but it was required because the 620 has weak amplification.. The X1 will blow you away though....
DannyUK