Clio09, it seems to me that other builders can get a bit closed minded on this topic of parts quality in terms of their impact on the music played through their gear. I have owned the RM 200 and thought it was good sounding if perhaps a little solid state like for my tastes. The RM9 was owned by a friend. My friend did replace several key caps to great effect in that amp. That amp certainly realized a HUGE leap forward in sound with the better caps. Yes, the original caps were still operating to full spec etc...Parts do make a difference and bring out the very best possible in any design.
Atmasphere has said it best in his posts above. The design is tantamount, but top tier parts perfect and can complete a great design. Builders should be open to this fact. Yes, wire, connectors, caps, resistors, volume controls etc do make a difference that can be heard. No snake oil here, no obsession on a wrong path. Instead this obsession in parts leads to better sound and learning.
Boutique caps can be very expensive and that is indeed a righteous reason not to use them, but don't get miffed at their use and passon for them. To do so is to stay put and not learn.