The word 'drift' may be a misnomer here. "Shift' might be more appropriate to use. When these radios are first turned on, that is when the shift from center freq is realized. Until the radio's chassis reaches parity with whatever ambient temp is present after components heat up due to current draw, it will then 'drift' to that center freq. Now - of course - all radios shift and drift. However, a Cobra 148GTL will do this far less than any Galaxy will; and sometimes isn't even noticed if the temp is close to the temp of the room when the radio was originally aligned. Unfortunately, one cannot say that about a Galaxy.
If the Galaxy engineers had designed the Loop Osc/Output Osc circuit closer to the 148's chassis; then this subject would have little reason to be mentioned at all. Never had nor worked on a Galaxy that didn't have considerable shift and drift. Never.
Of course I'm sure you know all of this. But you raised a good point for any newbee that wants to understand what is happening when this subject has been raised,, as it has been done here.
You live in the mountainous area around W.VA/OH IIRC, Mudfoot? Since temps can range wildly in a mountain environment, you should see a greater shift on a December morning then those of us living on the W Coast would know. It is all relative to the temps around you . . .