I may finally order the Semcycle freestyle uni I’ve been wanting for a really long time, but I don’t know if I should get the upgraded seat. I definitely want to use either the Nimbus gel or the new KH street saddle on this particular uni, but maybe the Semcycle seat converted to air for distance riding is not so bad? What do those of you who have tried it think? It costs $15 for the upgrade, but that’s a waste of money if it’s not comfortable.
what, nobody’s made one of these relics comfortable? 
The Semcycle air seat is an old school air seat design. A more modern design with an air pillow under some foam is better.
There are better saddle options than the old school Semcycle air saddle.
I’m now using a full foam saddle on my Coker. More comfortable for long rides than my old air saddle (air pillow under foam) and much less fuss. As soon as I can get a new KH Fusion saddle (with the new foam design) I’m going to try the new Fusion foam on my Coker (with a CF seat base). I’m thinking that’s going to be the ticket for a better Coker seat.
If you are doing freestyle on a freestyle uni, then an air seat is not a good idea. You will catch your foot on it. Slim, tight, firm, out of the way is the key.
If you are doing distance, then don’t get a freestyle uni.
The Sem seat upgrade is a little weird compared to other saddles. If you are doing freestyle outside, you will cut through the cover quickly, especially on the front edge. In this case, it is better to have a saddle with a replaceable plastic front bumper that will last a lot longer when impacting hard, rough surfaces.
John Stone swears by the Sem air saddle for distance, but then again you are not doing distance.