Considering a change from ARC LS3b to LS15

You guys have been so much help in the past and reading through old threads I know this is the place to ask.
I currently am using an ARC LS3b with the balanced outputs to crossover to amplifier and using the Direct Mode for CD playback.
I have zero complaints about this preamp and if I had to, could live with it for a long time.
That being said, I would like to venture into tubes and wish to keep the XLR connections to my crossover and amp and look at getting a CD player with balanced outputs.
Would the LS15 be a sonic upgrade to the LS3b and do you guys feel its a decent pre to cut my teeth on regarding the switch to tubes?
I run a sunfire bi-amped to ML sequels through an electronic crossover and a Denon DVD3910--for now.
Thanks in advance.
If I were you I would wait and save up for a ARC tubed preamp further up the range. A Ref 1 or 2 or 3 etc. Especially if you are happy for now.

The Reference stuff is pretty timeless and all excellent in their own way. Of course you can keep upgrading until the end of time, but I would take larger steps up the ladder. Don't waste too much time in the midfield.

Good luck.
Hi there,I lived with a ls 15 for a few years,and really enjoyed the pre.It responds well to different tubes and powercords.Its a fine pre amp for the money,in my book.