Someone suggested to me to try Optimum polishes and the excel propel pads (with a range of medium to aggressive) from Patrick at
http://www.exceldetail.com/ with a 6" backing plate. Since I have gone to this arrangement I have been much happier with my PC for getting swirls out
Before that, I had gone your route, I had used the Meguiar's yellow pad with both the speed glaze and the DACP. Both are good products, and even the yellow pad is good, but I found all polishes work better with an aggressive pad like the Excel Propel 2 Pad, which also does not marr on most finishes with the Optimum Polish.
Sometimes even this combination is not aggressive enough, and I mix OP with Optimum Hyper Compound to give it some extra boost. However, I have found from my experience a PC with numerous pad configurations and compounds WILL NOT ALWAYS REMOVE ALL PAINT DEFECTS and SWIRLS, and sometimes it may be necessary to resort to a Rotary, but for most customers they will be happy with a finish from 5 feet away. If you going to get rid of all swirls and defects, you are going to have to remove some paint, and a rotary is probably the best way to go to get the perfect finish. I have been told some types of Ford paint is very very difficult to improve with a PC from Mike Phillips at Meguiars and that a Rotary is needed to removes swirls.
But I'm not saying to go out and buy a rotary!
In most cases, if you have a good selection of pad choices from medium to aggressive, and have a good polish like Optimum which is real user friendly, and you already have DACP (which can be a PITA, but is effective) you should be able with a little practice and reading about techniques, be able to achieve the finish you want to achieve.
(If you are on a tight budget and can only afford to buy a few products, I would suggest the orange Propel 2 Pad from excel and the Optimum Polish, and you should see much improvement in your swirls. If on a bigger budget, buy a range of pads, and even the 4" propel pads are a great deal.).
Goodluck in your detailing, there is no black magic in detailing, just good technique with good products with a lot of hard work. If you want to learn the proper techniques the quick way, buy the video from show car garage.com from Mike Phillips, it comes highly recommended from beginners to experts.
PS Unless you are an experienced user, I would be very careful using the burgundy Meguiar's pads on a PC. These pads are designed to be USED ONLY WITH A ROTARY, and for most users, according to Meguiars, will marr the paint. If you only have small swirls, but the car looks good from a slight distance away, I'm not sure you would want to induce marring into the paint to try to get ride of the swirls with a PC with this particular cutting pad.