I have the Raptor which as far as I can tell is a carbon Baron. I've dropped the chain and changed the bars pictured to a swivel stem with the M5 vee bar. http://www.flickr.com/photos/brecumbent/2153458016/
I'm running a Terracycle idler. There are no chain rub issues for me BUT I need the full road width to do a U turn. I have a dual front setup with a 60 tooth ring. The bike is beautifully stable - my max. speed so far is 70 kph but there's no indication that it would misbehave at 100.
I can't speak for the Fujin but I did briefly own the Seiran SL and the Challenge build is excellent.
In favour of the Baron is the fact that the Optima bikes are a 'system' - you can visit their web site and buy off the shelf accessories.
I own an Optima Lynx for touring and IMO the dedicated touring bike is a far better choice than the Baron.
It's simply more comfortable and already set up with racks. I wouldn't want to tour on the Raptor. It would be perfectly feasible to tow a BOB (which would be my choice rather than panniers,) but you sacrifice comfort for speed.