I had a 30 and sold it for the 36. The 30 is a great gun if, and that is a big if, it fits your hand. The grip is fat and unless you have a big hand or long fingers, it may give you problems. My 30 would beat-up the first knuckle of my thumb pretty good. The first time I used it in an IDPA match this summer it drew blood from that knuckle. I realized that I needed a gun with a better fit FOR ME.
Handled the 36 and it fit MY hand/grip much better than the 30, so I bought it. The recoil/muzzle lift is more with the 36, it is noticeable, but it is not significantly more. I get a better grip on the 36 than I did the 30, so the extra bit of recoil is negated by the better grip. After the first range session, I put an Agrip on it and this thing is amazing. It is super thin and provids great traction. Any Glock I buy in the future will be adorned with the Agrip.
The 36 seems easier to conceal and much easier to wear all day for me compared to the 30. Would suggest you look at the Hume line of holsters at
http://www.wrbss.com. Great holsters at great prices, and Bill from wrbss is great to deal with. Lastly, the 36 has 4 less rounds than the 30, and this is a consideration.
I would strongly suggest that you should shoot both before you buy. Best of luck in whichever you choose.
Regards,
Frank