I purchased my Printerbot Metal Plus about 18 months ago factory built, not a kit. I didn't want it sitting on my front porch all day so I had it delivered to the place where I work. Thirty minutes after unboxing it I was printing a pawn for a chess set in green PLA. I was mesmerized watching it grow layer by layer, as I'm sure every new owner of a 3 D printer is upon seeing their first print.
People would stop by my office to watch it take shape. The owners' young daughter happened by and said "Is that a 3D printer? Why do you have a 3D printer on your desk?" To which a friend who was standing there replied "Because it's awesome!" Exactly!
The solid metal build and open nature of the Printrbot encourages you to tinker and change it. I printed a cable chain early on when I saw that the cable management system needed some work. The look on someone's face when they get the idea that the printer is printing parts for itself is priceless. I added a LED strip to light up the print bed. I added a filament roll holder. All easy to do because the Printrbot is so open. You can make it your own.
The original UBIS hot end was a great entry level part, but I've since changed it out for an all metal E3Dv6 hot end. The result is finer, more detailed prints. The UBIS2 hot end that Printrbot is now shipping is all metal too, but I have not printed with it.
Aside from the hot end, the rest of the mechanicals and electronics are original. I've printed many times a week for over a year and a half and it's been a true workhorse. I've started designing and printing functional parts for work using NinjaFlex, Taulman Nylon, and PETG. I've yet to find something it can't handle.
Of course, there is a learning curve to any 3D printer. Brook Drumm, the CEO of Printrbot, famously opened a video on his site with the blunt statement "3D printing is hard." He is correct, and you will learn this early on. But by trial and error and the help of the online printing community you will get better and better.
Overall, my personal experience with the Printrbot Metal Plus has been great.