By the way, I know some people may have issues with the Manfrotto QR plates (the fact that the system wobbles even when locked in) but I think the bigger problem is the friction lock on the ballhead- so even if you switch out the QR plate for an Arca-Swiss style mount you don't resolve the main issue.
I had minor issues with both, actually. I started with the 488RC2 ballhead, and that head 'settles' under load (you need to 'aim high' to compensate, by a varying amount depending on the lens), plus there's the issue with the RC2 plate being loose even when locked. The Manfrotto 468MG hydrostatic head solves the issue of the settling ballhead - that thing locks
tight, and with minimal effort. Replacing the RC2 clamp with a Wimberley C-12 solved the plate issue, resulting in a very good ballhead.
Still...a 468MG plus Wimberley C-12 combo is over $300 new, and that's pretty close to the Really Right Stull BH-40 at $375. I bought the 468MG used for a great price, but IMO, if buying new the BH-40 would be the better way to go.
FWIW, I am actually selling my Manfrotto 190CXPRO4 and Arca-Swiss converted 468MG - the buyer is due to show up in less than an hour. Nothing 'wrong' with the setup from a support standpoint, I'm selling it because I want something shorter as a travel tripod. The 190CXPRO4 fits in my Storm im2500 carryon hard case, but barely and only with the head removed - I wanted something that would fit without removing the head, and not compromise stability. Not coincidentally, a Really Right Stuff TQC-14 with BH-30 LR is on a UPS truck for delivery to me this morning.

The RRS setup is much shorter (tripod + ballhead are shorter than the 190CXPRO4 legs alone), lighter, the same height with the center column down, and is substantially stronger. How much stronger? The legs are rated at 25 lbs, but to give you an idea of how conservative RRS' support ratings are, check out the
video where RRS owner Joe Johnson puts a medium format camera on the 25-lb rated tripod...then swings
himself from the legs).