can't speak for RG but i swapped out my stockers for J&M 7.25s on my SG and it was a very nice improvement. No amp.. Easy install, complete plug and play....no splicing or soldering.. and IMO well worth the $250 i paid... It's plenty loud for me.... MUCH better sound quality
I got the 6 1/2 adapters and added infinity kappa's 6.2 -- they have been on the bike for two years now -- excellent for less than $100 (online) -- stock speaker are not that good
The only time I even slightly enjoyed listening to the stock speakers was sitting in a quiet garage with the engine off. I have the Hogtunes with an amp and there is a huge improvement and I enjoy music all the time. Put the J&M 7.25s without an amp in the wife's SG and that was a huge improvement. If you did that alone you would be much happier. Not sure what my Hogtunes Speakers would sound like without the amp. Their performance with the amp is basically the same as the J&M without the amp.