ceet make nice tall seat foam, but in the last 6 months i have bought tall foam for 3 of my bike, 2 took two to get right. the first foam was so soft you could push down with your hand and touch the seat pan. but both times i got a super soft foam, i just called them and they sent me a better one. if you don't like it they will make it right. i had a sdg tall seat assembly on one of my cr250s, it pretty much was the ugliest seat i have ever seen. i didn't line up with anything, was loose where the tabs are, just not right. not sure the chinese got the mold right for the seat bases, as mine was terrible.
factory effex also makes tall foam. never tried them though. if you are over 6 foot, more than likely a tall foam will help your transition from sit to stand. for me it helps me move around better also.