I used to play GEM keyboards and I thought they where very easy to operate.
The styles are great and you can use lots of user styles. The board I owned last was a SX2, the pro version. The keys felt great, very similair to the roland pro keys, not that plastic feel at all.
One of the big advantages for me was the option to expand your sounds with new samples. In those days i bought some awesome sounds from GEM.
The only thing i did not like was that in some sounds did not sound good all over the range of the keyboard.

When I moved to the US i had to sell al my gear. I recently got a Roland G1000 but when I was looking i tried to check out GEM.

I think they are very good keyboards but the reason that they are not that populair is bad marketing in the US. Nobody has them in stock, their agent in the states in now Peavey.

Strange though if you know that General Music owns their own PA company (LEM) back in Italy. I used to have a mixer, amp and speakers from them who sounded real good too.

I am sure that a lot more people would use General Music if they would improve their marketing strategy. The SK880, SK760, WK6 and WK8 are high end instruments with about the best specs in their class

My advice, try to find one, try it out, fall in love with it and buy it.