After a production lag late 2002, MVVS corrected some gas flow restrictions in the early 2003 production engines. The redhead came in April, and was a cosmethic change only. I must admit it is prettier that the colorless gloss anodize.
To get those 3.8 hp, you need all the tricks in the book, and the MVVS tuned pipe. It has been done, so the hp figure is legitimate.
3 hp @ 8200 rpm with APC 18x8N (personal measurement) is a better figure, because we tend to prop the engine way below the mazimum rpm, and get better performance out of the prop that way.
With a good high volume Pitts type muffler, the tuned pipe figures can be approached, with no more than 100-400 rpm loss. The exhaust volume must be at least 400cc.
Glow will always give a better performance in the same engine. The glow engine will also be lighter, less reliable, and you need a tank twice as large, so the 250 grams gained will be largely canceled out again.