It's funny how things ebb and flow, 12 months ago alot of cleaners were wanting bigger TM's because of water cooled angines and more power but the trend has reversed or more likely the readers on here have changed as most now are looking for smaller TM's, John Kelly has a new one as do Hydramaster with their 318 and Dave Ingram's light weight version.
I think you can't check reliablility as all units haven't been out long enough to say that they are the number one, weight must be taken into concideration as size as well.
Shaun