As above, had gel in the ZZR seat, it cost a lot and I don't think it helped that much.
This time around I just asked TA to add a bit more foam / use "better" foam or whatever, he told me about the lack of any foam towards back of stock seat and said he would do a plush pair of saddles for me - and I reckon it is much better than having gel (which is quite hard stuff)
Maybe gel works better for the bigger lads who can crush any foam known to man, but for my bony arse more foam gets the vote.