I had a Brother Innov-is 15 to take to classes for a while - I did sell it as the only thing I personally didn't like about it was the 7mm stitch width, apart from that, it was brilliant, and a pretty good price too. I am currently very happy with my old Bernina 801 to take to classes. I don't take it in its very bulky case, it fits quite nicely in a Sainsbury's 'bag for life'
All mechanical tho, so no needle up down, which I agree, is a pretty good feature to have!
Good luck in your search, it's quite exciting!