First I'm sorry for the cross posts. I don't know how to eliminate them. I'm not an expert like BenT

My experience with Bruce Tassi is both the same and completely different than Christophe's. 
I contracted with him to do a gas to diesel swap. We agreed on a price and there was a time estimate. 
My experience was that unless another list member went to the shop and fussed about it, nothing got done. 
Which may have been good because everything that was done was done badly, to the point of an exhaust system being welded up that would have been a failing grade in a beginning welding class. Wish I had taken pictures because it's difficult to believe now that anything that badly done could have been offered to a customer.
This was after the time period for the whole job was past, long past and what had been done was the gas engine had been removed, and the diesel engine cradle had been bolted in, that's it. I had the vehicle towed out of his shop at that point.
He charged for the work that had been 'done' but at least he did not try to hold me up for the whole price agreed on.
I understand that if you know what you're doing, keep a close eye on things, and insist on the mechanics that actually are competent it's quite possible to get a job done, done right, and at a decent price.
The upshot of all this is I'll never go back to him and advise anyone who does to keep a weather on things, know his personnel and their capabilities, and check everything.
JMO. Your experience may vary.
Mike