are all basically the same gun with some differences in how the line is rogged.
JBL has their own trigger mechanisms and muzzles, and Riffe has a third.
Then you get into the exotics (e.g. Wong), which I won't go into as they're in the nosebleed range in pricing.
The Riffe is not the gun for you if you want to freeshaft, as the line is the front shaft guide. But it is not significantly slower to reload than a JBL or Biller once you get the hang of it as a lineshafting gun. It is HARDER to reload, in that you probably want to chest load it, but that's how come it has more "oomph" than the JBL!
I own a JBL and a Riffe, and shoot both. For wrecks and reefs I prefer the C2x over the JBL; my JBL is a "backup" gun.
If there's a difference in reload times its so small (a few seconds) as to be irrelavent to production when hunting. I used to find the Riffe more difficult to load but a couple dozen dives with it changed my perspective on that issue.
SS guns are nice, but IMHO overpriced, at least in "commercial" trim (the only ones I think are really nice.) They make Riffe's look inexpensive side-by-side and I've yet to have someone offer me one to shoot so I can evaluate it side-by-side with my C2x to see if the hype is worth it. Maybe some day someone will show up on my boat with one of the SS Commercials and let me have a dive or two with it, so I can get some shooting experience with one.
The regular SS guns don't appear much (if any) different than a Sea Hornet, and in that regard they are IMHO WAY overrated. I've shot the genre (the Billers and Sea Hornets are essentially the same gun) and they're ok, but nothing special - kinda like the JBLs.
The Riffe C3x is, IMHO, too long for a reef gun. I own one and its a nice "short" bluewater gun, but its swing time is just too slow around reefs and wrecks. I don't use it often, as I'm usually spearing aronud wrecks and its just too much gun for the application. The C2x isn't much shorter physically, but "feels" MUCH shorter and easier to maneuver in the water.
Between the JBLs, Sea Hornets and Billers (and SS guns other than the Commercial Series), all of which are two-piece (wood) guns, I prefer the Riffe (whcih is a one-piece gun.) You're not dependant on a center section (which holds the trigger assembly) to stay together; the Riffe is a solid piece of wood routed for the trigger assembly.
A Riffe C2x can be had for just over $300. The JBL will be considerably cheaper. Spare shafts and such for the JBL will cost less as well. If you get the JBL, consider powering up one size on the bands (go either one size "wider" if it will fit in the muzzle, or one inch shorter if not); I found the stock bands on the JBLs to be pretty anemic. THe only caution with this is that the ultimate strength of the JBL mechanism isn't in the same class as the Riffe.
So if the $250 limit is "real", then the JBL isn't a bad choice. If its a bit "soft", then look at the C2x. If you want something in the "commercial" line (e.g. quick line/free shaft switching, etc) look at the SS commercials, but bring your checkbook 'cause you're gonna need it. If you're considering an SS gun other than a commercial, you're basically buying a Biller/Sea Hornet, and is in the same class as the JBL.
All IMHO of course.