I'll try and answer this for Dwight, because he has a lot of preparing to do for this upcoming Spring Smallmouth Extravaganza he is going to put a whoop down on.
I have both the 853C JWR and the 843 MBR. The 843 MBR is a fast action rod (as opposed to the extra-fast action of the 853C JWR). This slightly slower action seems to open to door to techniques like crankbaits, jerkbaits, topwater and other treble hook style lures (as a side note, there are a lot of guys who like an extra-fast action rod for jerkbaits & topwater, but I am not one of them). Also, the action and power of the 843C MBR is just perfect for Spinnerbaits. As for the 853C JWR (and other in the JWR series), these are really geared towards jigs and plastics. That extra-fast action really allows for working those bottom contact baits and the little more stout blank of the 853C is good for pulling fish through any type of light cover. With that being said, if you fish plastics & jigs like 90% of the time, then I would be looking into the JWR line-up as it will fish other techniques. If you want just one rod to really handle a lot of situations, then the 843C MBR would be my choice.
As a Disclaimer, NRX rods are very addicting and you may say you just want one, but you will never be able to limit yourself. You will feel the comfort and sensitivity of that 853C JWR or 843C MBR or whatever you choose and say, "Maybe I'll just get one NRX finesse set-up?" With that you'll get the NRX 852S JWR. Then you'll say, "You know, there is some heavy cover I really want to get that frog through or a punching rig in," and you'll end up with the NRX 895C JWR or NRX 916C UBR. Then you'll say, "I really want a NRX jerkbait rod," and realized they don't make one, so you go and buy a NRX 843C MBR and take it to a professional rodmaker to modify it to get the action you want. It's just a never ending sickness. I just want to warn you before you get into that "gateway" NRX rod. Good luck in your search.