There is a lot to like about companies like Decware--they are generous with sharing designs and engaging with their customers, their construction is pretty solid, and prices are quite reasonable. But, the two amps of theirs that I heard I simply did not like--they sounded a bit lifeless and lacking in body. One must hear each candidate, or have the ability to either get out of a deal or accept some loss in trading (not much of problem with Decware because it appears to retain value) if you don't get to audition the gear.
This is the case with any amps, but, I think SET amps are particularly sensitive as to specific use because of their low power output and their typically quite high output impedance (meaning that they often don't work well with low impedance speakers).