My GQ has the weber conversion on it, it was done by the previous owner, Im not 100% why, I think it was for better fuel consumpt?
Anyway, I don't have any major problems with mine, other than it has a very very slight miss when idling that I find extremely irritating. I don't think most other people would even pick it up, but it irritates me to no end.
Something to think about - each time I talk to Graham at G-tech he mentions that we should look at putting the standard ones back on as there is the issue of fuel starvation (or is it flooding? I cant remember?) on very steep inclines. I haven't had to do any very steep ones, so haven't experienced the issue, but Graham is adamant about it.
Personnally I would actually prefer to have mine put back to standard just so it is standard again. But then again if it aint broke, don't fix it.