I wanted some lockers for my Tremonti SE Custom. It was staying in tune as well as any non locking trem bridge without the locking machines, or as well as my Studio with the phase3 lockers. I wasn't really expecting an huge improvement in tuning stability but moreso, I was looking forward to the faster and easier string changers.

Buddy at the other forum recommended the Shaller M6 straight drop-ins for the SEs at around $75-$85 shipped.
I found an eBay seller willing to ship a set up here to Canada for $85.
I put em in (and yup...straight drop-in..no drilling, enlarging, bushing...nothing..even used the guitar's original screws.) and as expected, tuning wasn't much improved. Maybe a little.

When they were recommended dude told me that the hole in the tuner shafts would be JUST above the headstock face but not to worry. He was right again. It's REAL close and would almost give cause to worry but...you don't put any wraps on...and...more break angle over the nut isn't a bad thing.
I'm very happy.

BUT..as usual...the day after ordering, a new thread popped-up comparing the Shallers to the Grover or Gotoh (cant remember which) "self lockers". They look really cool. They're cheaper AND have a higher gear ratio (18:1) than the Shaller's 16:1. Had I known about them I probably would have got those instead although the self locking business freaks me out a little bit. Not sure why but...
And THEN...after the M6s got here and I installed them, for some reason..AFTER the fact...I eBayed PRS Phase2 tuners and saw plenty of them fur under $100 :-O I just assumed they would be WAY more than that. Thought at least $150 or $200. I don't think they are a direct replacement in the SEs though?

Anyway...for any of you who may be thinking of adding some lockers to your SE, the Shaller M6 locking tuners (careful, they also have M6 NON-LOCKING) work very well. They lock perfectly without the use of any tools or coins and give plenty of break angle. I think that's the issue when trying to put Phase3s into an SE?...not enough break angle? The Grovers have a higher ratio but the Shallers are nice and smooth and work perfectly.
If you want drop-in lockers for your SE, $75 should get a set of Shaller M6s to your door. Another 5 minutes and they're in the guitar.
Even if your SE doesn't have a trem, the lockers knock about 90% off of the time it takes to do a string change.

Now, I'm not sure of the advantage of "low mass" tuners like the phase3s. The Shallers are anything BUT low mass. If anything, my Tremonti SE Custom has MORE sustain than before. None more sustain is how much ANY guitar has than this one.

I am not affiliated with Shaller...obviously and I don't get anything for raving about them. Just trying to do a public service by assuring anyone thinking about lockers that the Shaller M6 work perfectly and are cheap.