Here I go again !!
Went the distance with the Flex today on the Merc - 3/4th the distance in fact - I have left the Sealant step for tomorrow. Hope the weather gods will co-operate.
Here are my two bits - apologies for the long post - hope some of you find it useful.
The paint condition of the Merc is very good (there are swirls but you have to nitpick to find them). So I used only finishing polish - Menzerna PO85 RD. The recommended pad is LC CCS Grey, but that assumes that a compounding polish has been used prior. As this was not the case I used a LC CCS white pad which has some cutting power. I used OPM setting 5 - which is the cutting speed - with some trepidation initially but settled down quickly. The result so far has been outstanding !!
For folks who stay in apartment complexes I would recommend that you get a extension box made. And ask your electrician to tap into your apt line from the meter room.The polisher is a 900W unit. That is like a 1 ton AC being used for 4/5 hours. Other residents may not like your car as much as you do. Avoid the extension wheels, the wire of those things may overheat. Use outdoor cable (black-round-thick). Similar to the cord attached to the polisher. Put a fuse on the extension box - JIC.
As far as the polisher is concerned - I have not used others but they cannot be any better than this. It is heavy (2.5 kg) - Mike Phillips at Autogeek had mentioned that you need "upper body strength" to use it - I had found the comment amusing - I will acknowledge that it is true. Because of the direct drive feature, when you apply pressure on the head only which is easy to do, the unit sometimes tends to "walk on it's own" so for steady work you will have to put pressure on the whole unit using both your arms and keep it FLAT on the surface while you do so. When you hand polish your arm / shoulder muscles tend to get overworked, with this unit they tend to get fatigued because of the steady pressure you need to put on the whole unit with both your arms. When you do curves you need to be alert because if it "walks" it can pull you off balance and if you let go OMG.

. The unit runs hot but that is OK. If it gets overheated it automatically will reduce the OPM till it cools down. But mind you hot is HOT so don't grab the unit by the casing on the head. Always the handle.
The Merc is a large car. I divided the bonnet into six sections, the rear into three, the doors into two and the roof into four with masking tape. Taped the trims and the emblems etc. Ran out of tape in fact. The car requires two rolls. A six inch snake of polish on the surface, couple of squirts of pinnacle pad conditioner (QD or water will also work) to moisten the pad (only initially), spread the polish with the polisher off, start with setting 1 and get an even spread of the polish, bump it upto 5 and off you go. The bonnet and the boot were a breeze - 8 section passes for each section- and the polish nicely disappeared leaving a haze (buffing cycle). Buff with a MF towel and WOW ! you can almost see through the paint.
Piece of cake I thought and then I started on the vertical panels -
IT IS HARD - you willl need your "upper body strength" right there. First, you need to sit down when you do the vertical panels. A low stool is a must - something like a Kid's potty. And then apply pressure and keep the DA flat on the surface - mind you, the weight of the unit is working against you here. Imagine holding a 2.5kg weight suspended with your extended arms while it it trying to "walk" every now and then. With 8 section passes for each section this can be tiring. I took a break after each panel. I guess the other DA polishers are easier to handle in the vertical panels. Once you get used to the flex it will be better. But the vertical panels are always a struggle.
The roof was also a little awkward simply because of the size. I needed to stand on a chair to do the roof.
As you polish and the pad soaks up some of it, it will start slinging out little globules of spent polish - when that happens it is time to clean the pad. I used a brush to clean the edge of the pad with the polisher running - be careful with your tee shirt or the polish will land there. For the center of the pad I used a towel pressed into the pad. Hold the polisher firmly when you do this - oh and sit down.
Finish off with a full wipe.
I am sure I shall improve with practice. The rookie results are very encouraging.
Washing the pad after - should be done immediately before it dries. I used the pinnacle pad cleaner. It is good. I think it has some degreasing type agent in it. Few squirts on the pad let it soak use the brush to agitate and then rinse - the polish leaves the pad. I wonder how difficult it will be to get the Collinite 845 off. Only cold water to be used - I guess because of the adhesive on the velco backing.
Tomorrow is another day !
Rgds