MikeYaYa, Yes, Rowland amps work very well with Raidho speakers, but...
Let your speakers break in and settle down first... Once their behavior as stabilized, you will be able to determine what your Mcintosh MC275 does well with them, and where it falls short, if at all. If you rush now to get a new amp -- of any brand / model what so ever, you might correct some temporary sonic flaws of the speakers, that in just a few weeks, will turn into some new annoying overcompensation.... And down the eternal rabbit hole you will go, seeking yet a new gizmo to correct the over-correction.
So... let things settle... Enjoy and sit back.... If you discover any frequency humps, adjust the speaker positions/orientation until the seem optimized.... Then listen a lot more.... Are you in Nirvana already?
Hmm... Knowing you are a "suffering audiophile", probably not... Might be still time to think about a Rowland Continuum S2 integrated? ... Or the brand new Rowland M625 S2 stereo amp... Or may be, you want to explore what the High Fidelity CT-1 PCs do for living instead... Yes, these PCs designed by Rick Schultz are in fact amazing, but Until the dust settles in the system, you would not be able to tell their magic.
Besides, your system as is, may already be emitting the ultimate cat's meow!
G.