which is more musical? A REL or a SUMIKO subwoofer for two channel only?

More thought and technology put into the REL yielding better sound.
Check out the explanations provided by REL on Youtube, see the "REL Acoustics How To"
Talk to any store that carries both SUMIKO and REL and ask them their opinion.
In addition to the above, the REL customer service is there 100% to assist if needed.

Hi Lak, may I ask what REL model are you using?
Hello AudioConnection, a Vandersteen 2W can be had for $350 cash, locally. Where’d it stand in performance as today’s standard, Are the 2w-Q and Sub-3 much more superior than the original 2w?

REL T/5i, REL T/9i, SUMIKO S.5, and S.10

NasamanA local 100 pound 2w for 350 with the correct latest high pass set correctly would be a great start.just make sure it was well cared for.you can pm me to attain the correct x over choice. Best JohnnyR 

My update,
I bought a REL T/7 and it is very good, very tuneful for my 2-ch listening. It’s nicely adding to the lows, and like many others had mentioned, it’s def not shaking the house and that what I was looking for.

Saw great potential of the T/7 and quickly bought the S/3. Wow, love it.

Note: If you are looking for a sub that will play (much) louder than your speakers, REL will disappoint you, horribly.

Thank you AudioConnection for tips on Vandersteen 2W Sub but, for now, I decided to go with RELs for easy/quick plug & play connection instead of spending more time researching on what to do with that Vandersteen Sub's X-over network.