I've got a Taz 2.1 from Lulzbot. It's tons of fun, but I had really hoped I'd find some joy in the ability to use it for rapid prototyping. I've done some minor stuff with it, but this weekend I finally got to build a thing which I designed that was not trivial. 
One of the final pieces being printed
I also took all the scraps and did some ad hoc materials testing. A 6mm standoff will take a 1/16" drill bit just fine, and then the resulting hole will hold an M3 screw pretty well.
On larger flat surfaces, drilling was also easy, though with a larger bit and too much force, layer separation can occur. Being able to get in 0.1mm tolerances is pretty impressive. 
Layer Separation, and a screw hole
Super glue works surprisingly well on unsanded PLA, but I can't get my corners to stay down perfectly
More Separation, More Screws.
I haven't tried cutting it yet, I assume that a very fine blade is going to be the most useful.
16th February 2014
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I'm Issac. I live in Oakland. I make things for fun and money. I use electronics and computers and software. I manage teams and projects top to bottom. I've worked as a consultant, software engineer, hardware designer, artist, technology director and team lead. I do occasional fabrication in wood and plastic and metal. I run a boutique interactive agency with my brother Kasey and a roving cast of experts at Kelly Creative Tech. I was the Director of Technology for Nonchalance during the The Latitude Society project. I was the Lead Web Developer and then Technical Marketing Engineer at Nebula, which made an OpenStack Appliance. I've been building things on the web and in person since leaving Ohio State University's Electrical and Computer engineering program in 2007. Lots of other really dorky things happened to me before that, like dropping out of high school to go to university, getting an Eagle Scout award, and getting 6th in a state-wide algebra competition. I have an affinity for hopscotch.