Let's be clear what we're talking about, as there are several very different Weber conversions.

The most common one uses a single downdraft progressive carb (meaning it has a primary and a secondary barrel). It's simple, fairly reliable, and offers less performance than the original injection. It's really a very small carburetor for a 2-liter engine, and I don't recommend it for sporty applications.

Very different from that are conversions using two two-barrel side-draft Webers. This is more complicated, much more expensive, and potentially offers more performance than the injection, although it probably doesn't do much for a stock engine. If you hotrod the motor, they come into their own.

Both require extensive jetting to really run right. They don't come that way, so a lot of non-ambitious people don't get good results. When set up properly, they can work extremely well.

You're most likely on your own working on the injection or Webers -- neither is something most garages understand or care about. I'd put my effort into learning all about the injection if you intend to keep the motor stock. Webers are just as complicated to understand.