well the only reason why i stopped learning XSI is because there is hardly any training for it, unless you wanna fork out £130+ for there dvd range that covers everything then there really isn't that much out there. I did some good work init but i couldn't go any further, iv only just started learning maya and there is simply so much more you can do with Maya and also so much quicker Iv got https://movielibrary.lynda.com/html/modPage.asp?id=150 which is well worth the cash, and its really converted me. i don't think ill go back to XSI unless alot of training comes out for it but by then ill will have learnt loads more with maya