The SEs with trems have decent tuning stability, it's mainly just the G string that goes flat if you use the trem too hard. A new nut and locking tuners pretty much does the trick, although it seems a lot of people here swear by the MannMade trem as another solution. I put the SE locking tuners and a Graphtech nut on my SE Tremonti Standard and it doesn't really have issues anymore