Have you changed your mind on the RapidAir system, or prefer the Aircom. This is of interest of me since I might get around to an air system in my new shop sometime this year (also looking at new 2-stage compressors like the Quincy)
To be honest, my only worry about the RapidAir coiled system was not having the lines perfectly straight. I know several on Garage Journal who have spent quite a bit of time getting theirs straight and they look good but most I've seen are far from straight and the owners really didn't care whether they were or not. I just think it would have bugged me long term. The RapidAir was the least expensive option compared to the rigid lines and I think it is a good system, other than the coiled lines.
RapidAir also makes the rigid aluminum piping system called the FastPipe system which is pretty much identical to the Aircom system as far as the looks and even the design of the compression fittings, unions, elbows and wall fasteners.
I looked seriously at the FastPipe system and waffled between that and the Aircom. I was able to get the Aircom only slightly cheaper but I think that was because the way they spec'd their full kits out fit almost exactly what I was looking to accomplish. Also the FastPipe system in kit form only came with a single wall outlet vs. the Aircom system came standard with the dual wall mounted manifold. The FastPipe system required the dual manifolds to be purchased at an additional upcharge compared to the Aircom. The prices for the basic kits however, were negligible between the kits. By purchasing 3 of the full Aircom kits I came out with only a few short pieces of tubing left over, dual manifold and a couple of unions. Other than that I used nearly every piece with little to no waste. The other reason I chose the Aircom was because Maddox Compressor who is local to West Haven carries the Aircom and my thinking was IF I needed a single component or needed to add anything it would be easier having a local source vs. having to wait for something to arrive via delivery.
Personally, I don't think you can go wrong with either system. I have had mine in service for 5-1/2 years now and I am still very happy with it and would do it again.
As for compressors, I don't think you can go wrong with Quincy. You will pay a bit more upfront but buy once cry once. I have had my dual stage Quincy for 30 years this year and it is still going strong with minimal maintenance.
When you get to that point if you want to see the Aircom system in person you are more than welcome to contact me and come and check it out.
Mike