As long as you already have the Weber, if you're willing to get it rebuilt or figure out how to do it yourself (likely less trouble than putting the stock carb back on), it's the superior option.
The mc2100 is loved because it is cheaper than the Weber and just as effective, iirc.
It's pretty easy to tune my Weber 34/34 dgec; my only issue was with the choke sticking and that ended up just being the choke flap needing to be filed down. Okay, maybe it would be more appropriate to say that I put the carb in its baseline settings and really don't notice any difference when I move the mixture screw, so I just leave it 2 turns out and adjust the speed screw until it idles low enough. It runs fine. Tuning the stock carb looks like absolute abject brain surgery, to judge from the instructions on the emissions label.
