Today i started a new character, i always sneak as much as possible. Helps with leveling sneak for later on.
I'm not sure if anyone else has noticed this at all but since patch 1.4, is it possible that the rate that sneak levels up has been altered in some way ? even with Thief stone active ?

I restarted my sneak character last night after messing up my save, but I haven't noticed any significant difference after a couple hours of playing. It may even be leveling faster, if anything.

My Sneak is up in the 60's, but it is leveling like it should for me since 1.4

I have to agree. I haven't noticed a change in the rate of leveling as far as Sneak is concerned.

I think after One Handed, Heavy Armor and Archery that Sneak is my highest skill. Even at low levels, I've had no problems raising it. In Morrowind, if it was a miscellaneous skill at 5, I found it next to impossible to raise it without visiting a trainer.

I sneak nearly everywhere I go and it has taken until level 60+ to max it out. I can't say that I have noticed any change between patches 1.3 and 1.4.