50% of the machines out there are the best in the right hands, when i first started i thought the best machine does the best job, but in 9 months using the same machine my results have improved 10 fold, all through lots of training and help from the guys off here
as long as it has a decent PSI, hot water capabilities and suction to get the water out, then the rest is up to you and your hunger for knowledge.
hope this helps
neil eric body