Welcome to the world of Mercedes paint !
I have never used D300 but know a lot about Meguiars 105, 205, and 101.
The only way I know of to really get the best clarity on CeramicClear Paint is a Rotary, lots of pressure, and a bunch of pads..
You could use Lake Country's older Purple Foam Wool pads in the smaller 5" or so size, or their newer version of the pad but I have not used the newer ones..
The older ones work fantastic but shred a little wool.. They will absolutely clean off defects really quickly, as long as you know how to manage the compound and the pad..
For your machine (which I also have), I would use lots of pressure, keep the pad rotation high, and the speed all the way up, until I found the best process for this particular paint..
You would need to keep the Meguiars 105 damp enough so it gets through its initial-want-to-dry-and-ruin-your-day-mode, and then it will settle down and polish up really nice and glossy..
It can be used all the way through to the end and I believe Todd has made a few posts and pics of him doing exactly that... I have done this as well and love this stuff for its versatility in doing so many different surfaces really well..
I have never had any good experiences with Surbuf but did try them out when they hit the BigScreen 10 years ago..
Just remember - you can use anything, adapt it to your job, and find the sweet spot and figure out its limit for that paint at that time..
Just be patient, dont rush - ever - you need time and full attention to get this right..
Sorry this was a pain.. Get some purple foam wool if you want to speed it up, or perhaps a Menzerna Compound with a more aggressive foam pad..
Dan F