I have a Ultimaker 2 and it is surprisingly good printing quality.
How is the software? Is it a fairly simple 'send to printer' thing? Does it accurately estimate the build time? Can it estimate material volume (for costing)?
I have it now for 3 years or so and have only adjusted the bed level twice, no other maintenance.
Only bad filament can cause it to jam as in not putting any plastic out.
This has happend 3 times in 600 hours of printing with this thing. The plastic is quite strong, do not underestimate that.
The ultimaker 2 has a socket for a second extruder but as far as I know of the company has never implemented it (probably because of good reason).
In my opinion a second extruder is a gimmick and you will never use it. The software is cura. It is accurate , simple, works always.
The build quality is top notch. And the print quality is as best as it gets with the extruded type printers. All these printers can use the so called glass fiber filaments etc... But in my opinion that is not needed.
https://www.3dhubs.com/talk/thread/thoughts-about-new-carbon-fiber-filament-colorfabbI have seen prints of makerbots etc but I was not impressed. Why spend double / triple the money for a equal or worse machine.
Ultimaker has been around for quite some time and makes great products (here in the Netherlands).
I always use the stock medium settings on my machine and to print you have to save it to a SD card and put the sd car in the printer.
You can download cura and have a play-around with it.
In my opinion it is the best machine you can get in the extruder category. All the cheap machines just suck, all the expensive machines do the same (or worse) for more money.
If you want really strong than just print your part and use it as a mold for harder material. Heck even use it as a mould to pour aluminium in it