Yes, the RS and RCA remotes will control the Vizio TV, using setup code 11178. Actually, nearly any UEI manufactured remote will operate power, Ch+/-, and Vol+/- on a Vizio TV. Furthermore, using "keymoves", doable without a cable, one can make all the other TV functions work.
Here's why: A remote communicates with a component (TV, DVD, air conditioner, etc.) by sending commands as a string of bits. The zeros and ones are represented by flashes of IR light, but the particular pattern of flashes needed to represent a 0/1 (called a protocol) varies among components. There are dozens of protocols. Besides needing the correct protocol, the remote also needs to send the address, or device number, that the component is expecting. Finally the command number that means e.g. Vol+ varies among components. But if you can find a setup code that causes anything to happen. that usually means that the setup code is sending the correct protocol and device number. Then it is possible to manually assign the desired command number to a particular remote button.
So what to do if your remote doesn't have the appropriate protocol/device number combination? Or, if it does, but most of the remote's buttons don't work, how do you find out the command numbers? For UEI remotes, go to http://www.hifi-remote.com/forums/index.php
and go directly to the Beginners forum and read the "Please Read This First" sticky. The Market Place forum has offers to sell JP1 interface cables. I strongly recommend getting the USB cable sold by Tommy Tyler.
The software is free, and the site is kept going by the enthusiasm of do-it-yourselfers. So the organization of the site is a little fragmented.
There are two main SW programs: RemoteMaster and IR. As a beginner, to control your Sound Bar, you would look in the file section and find that a rudimentary upgrade already exists which can do Vol+/-. You would probably also post about what you want to control, mentioning that 1517 is supposed to work, and some good person will reply, telling you what the command numbers for 1517 are, or perhaps simply posting an already finished upgrade which you can upload into your remote using IR.
JP1 versus getting a Harmony? You'll have to decide that yourself. In my situation, we have 3 teenage sons, 3 TVs, and a misbehaved dog. We like to have all three remotes be the same, and I'm not willing to spring for 3 relatively expensive remotes. Also, I like to operate a remote without looking at it.