chriz_batman said:
which do you think has better tone, clean, od, gain, features, sound, and even looks? which do you think is a better high gain metal amp? which has better cleans? and which do you have or own?
I own both a RK1 (since 2005) and a MK IV B (since 2007). Regarding looks, you can customize both amps (chassis, wood, grille, etc.) through Mesa's custom shop.
As for tone, I don't think it's fair to say that one is "better" than the other because they just sound completely different.
For metal tones, I think the RK has a much bigger sound than the MK IV: the RK has a huge spread of low-end thump, high end chime, and wads of gain. The MK has a really focused, tight gain that's pure cotton candy to my ears. It's not as big as the RK, but it has a very special personality that reminds me of metal in the late 80's and early 90's.
For cleans, my opinion is tainted because I have a RK1, and the RK2 underwent major changes in the clean channel by adopting the Lone Star cleans. However, I like cleans from both the RK1 and MK IV. The MK IV cleans sound "hollower" and "warmer" to me than the RK's cleans. It depends on what style of music you want to play.
Regarding leads, I'm going to risk being crucified by others on this forum and say that I like lead playing better on my RK than on my MK IV. I feel like solos are effortless on the RK Ch. 3/4 Vintage mode with lots of gain - probably because it seems "airbrushes" your notes and phrases into pure silk. Contrast with the MK IV leads where every note rings clearer than a bell - even with high gain. Maybe that's why I like leads better on the RK - they seem to cover more mistakes!
All in all, I'd recommend either amp any day. But, I'd say that the RK is more versatile than the MK IV. I can make my RK sound similar to my MK IV, but I cannot make my MK IV sound anything like my RK. Finally, note that the type of speakers and configuration (cabinet vs. single speaker) will make a huge difference in tone. I'd recommend a 4x12.