I've purchased from CWC, Devon and Buchanan's. The rims that came from Devon were polished flanged alloys like the Akronts from the seventies. The surprise was that they are made in Spain in the original factory that made the Akronts. A further surprise was that CWC owns this factory , which had sat idle for many years. They recommissioned the old machinery.
As far as the rim quality goes, in this case there was no difference between CWC and Devon. The price was much lower for the CWC rims plus they throw in extra spokes of each type required. Devon did not and I forgot to request them. My little extra spoke package with 2 spares of each type (8 spokes total) cost about $120 with shipping!
Buchanan's products are probably the best there is but the cost is the highest. On the Buchanan rim there is virtually no lump or flat spot at the weld. This is because Buchanans do a final machining of the rim after welding. On other rims there tends to be a very lumpy spot at the weld. The best is to ignore this spot when lacing the wheel. It makes the dial indicators go crazy, really can't straighten the short kink at the weld. End result is fine either way, but it is nice to see the completed Buchanan's wheel go round and round with barely a flicker from the dial indicators.
Glen