Above it All Roofing replaced the roof on our house and the detached garage.  They had to take off 3 layers of old shingles to do a proper job. 

The job went well for the most part. The contractor found a third layer of shingles that had to be removed, at additional cost.  People I’ve talked to said they should have seen the third layer when they were bidding the job.  
They showed up on time, worked very hard, were very pleasant to deal with.  The job was done quickly, and additional eave boards were replaced, again at extra cost.  
Overall, I would rate this as a very positive experience.  The work was done quickly and well.  We’ve had some rain since the job was completed, and everything seems to be watertight.