just out of interest I see they have both air assist and purge air for the lenses now (plus intake and exhaust air): Air assist and flame reduction - Glowforge Owners Forum
I believe the normal model has a port for you to stick a hose in and stick it out a window (take that, nature!) and then there's that optional charcoal and hepa filter doohickey that means you theoretically don't need to vent it although they don't seem to be able to say how long that will last or exactly how much replacement filters will cost. So yeah.
I also saw that the "Pro" model has some pretty must have features - a pass through function for "infinite" length material, a more powerful laser with better optics and crucially for me - better solid state thermoelectric cooling.
I think it's pretty interesting, mainly for my girlfriend who is currently enjoying her silhouette cutting machine for making various arts and crafts - this is an ideal step up given the focus on making it user friendly (and for that matter desk friendly).
My only real concern after reading up on it all is the cloud based functionality. If their service is down, then so is your glowforge... if the company vanishes in a year or two (or should that be month or two?), your glowforge is rendered next to useless.... I saw one video where the boss chap mentioned they had a "back up" plan using open source firmware which basically turns the glowforge into a somewhat expensive simple g-code following laser cutter... far from ideal really.
Balancing it all up, I decided to just go for it and stick in a preorder for one for the missus at the discounted price. Hopefully it will be great for her and maybe i'll get to use it occasionally! Now I just hope it turns up....