I'm not sure about the FG-36 but I hear the smaller gas Saito has been fairly problematic.

To be honest, I personally wouldn't go for the Evolution either. They do seem to work well but I just like some of the other options. Zenoah and Fuji engines are both great and are hard to beat. There are also a lot of low-cost engines coming out of China that run very nice considering their low cost. You may give up a little in factory support but they are still extremely impressive. Look for DLE, CRRC, XYZ, MLD and others. Hobby City has some unbelievable deals on 2-stroke gassers as well.