I don't necessarily associate gumwalls with lack of durability, unless you are speaking specifically to what is available in gumwalls in track tires? My Veloflex Master clinchers on the road were awesome and lasted a long time. The tread wore out before I had any sidewall damage. Even toured on those suckers on badly maintained roads!
I would think sidewall durability isn't that important for a bike that is indoors 100% of the time. It doesn't even leave the track and lives in a locker, but maybe thats why my experience with Veloflex Record was so unbelievably sh**ty.
I will consider those Vittoria Pista CS Elite's and look into the Stehers! Thanks!