I purchased an American Standard Furnace and AC from Air Tech West in October of 2006 (it is now May '07). The quote was very competitive and I was certain of the brand name already (it is a re-badged Trane unit..VERY SATISFIED!)
The installers took longer than expected and almost cost me $100 in having a re-inspection by enbridge (thanks to the inspector for hanging around for 2 hours).
The electrical to the furnace was wired NOT to the fusebox, but tapped off an outlet! It took 3 phone calls and 2 weeks to get them to react to this blatant breach of code. The installation is ugly, the drain line was (and still is) drooped across my floor to the drain as they were too cheap to trench my basement floor and properly run it underfloor. They forgot the AC cover and it took 5 more phone calls to get it even AFTER it had begun snowing. They improperly installed the gas line (read: small gas leak)and got my installation red tagged by TSSA. Oh and they really messed up the rebate forms, forgetting to get me the credits for my thermostat and for all other equipment, they put the wrong make / models on the form which delayed my rebate.
Don't go with these people, I LOVE the system but the service is poor and they aren't worth the small difference in price.