Tube rolling in Modwright LS 100 preamp

I just swapped the stock tubes (JJ) for Sophia Electronics 6SN7's and a Genalex Gold Lion rectifier. I was quite surprised that I didn't really notice much of a difference. The preamp sounds wonderful, really, but the SE's have been touted as a nice improvement. Perhaps I just need to be patient for them to break in. Any comments? Thanks.
Here is a link to other opinions:

Opinions on tubes are really diverse, except that most people really like the ones you can't afford, like Tung Sol round plates.

I'd call Dan Wright and be prepared to tell him what kind of change in the sound you would like to get and how much you want to spend and see if he can offer some suggestions other than the Sophias he recommends on his web site.

If that doesn't solve the problem, talk to a reputable tube dealer and get his more experienced advice. You can just do a search for "tube dealer" in the Audiogon forums to get some names. These guys charge a little more than the prices you can find elsewhere, but buying from them is cheaper and easier than trying to become a tube expert yourself.
Differences between tubes can be subtle, so you might want to listen to the Sophias for a while and then plug the JJs back in and see if you notice more of a difference after breaking in the Sophias and your ears.
I use Black Treasure CV181s (6sn7 equivalent) and a NOS Philips 5AR4. Find this a very musical combination and the BTs an improvement over some NOS TungSol 6sn7s - sound stage, depth, bass, separation