one thing that was not mentioned is that the $1595 Wren comes with a hand starter and if I am not mistaken an air system is not a required accessory with the wren. Also for about a $100 more you can have a semi auto start system where the starter motor is mounted to the turbine, but the battery for it is only connected whenever the engine is started, thus saving on board weight and $.

I've been doing a lot of research lately myself, and from what I can tell if you are looking at a 12lb turbine wren appears to be the best and no one on RCU has anything bad to say about it. Also the Artes Jets Bee looks to be pretty promising 1.4 lbs + accessories, and 4 oz per minute at full throttle seems to be really impressive also, it comes completely built with autostart for about $2200 US .