I've come to the conclusion that it has something to do with the vacuum directly or indirectly involved with the transmission and perhaps the throttle position (adjustable with the slide and other bowden cable to the gas pedal). If I adjust the bowden cable to the trans (see below), I get varying levels of the surge to the point where I really don't get any surge. However, it's never completely gone as after a long drive where things have warmed up a bit, the first stop or so it will have that slight surge. My mom has a 94 c280 that is almost in mint condition and literally smells like new inside and drives tight like new. I use it as a benchmark when I fiddle around with my car. However, I noticed the last time (I think because I'm specifically looking for it) it also had a slight blight of the rpm as it comes to final stop. Of course all this means is that if the car wasn't adjusted then something has changed, i.e., car is aging but adjusting it can alleviate the situation. Throttle bodies of both cars are very clean.

Side note: which you might see in my other posts, adjusting the bowden cable, throttle linkage can literally make this car drive differently like night and day. Smooth takeoff, nice shifts, good midrange. It literally tunes the car (despite the MAF, electronics, etc.) Unfortunately the combinations are infinite and I have now been trying to get the elusive setting I had at one point which was really sweet, better than OE (honest to you know who). Of course, couldn't leave almost perfect alone. It's been like the holy grail. So if ANYONE has some official MB instructions on this for some insight I'd appreciate it.