If you want to do a proper detail including paint correction (removing swirls) in one hit, you really need to set aside a whole weekend. Granted the dual actions take longer, but they're far safer to use in inexperienced hands. I wouldn't trust myself with a rotary yet and I've done 5-6 full details on various cars. It's still relatively easy to generate a fair bit of heat with a random obital polisher and it's not unheard of to get strike through especially on edges.
Using a machine polisher to get desirable results will take a lot of time regardless. You should only apply the polish in small sections (I would do tea towel sized areas at most) and you have to work this polish in regardless of polisher to get the results. Trying to do it too quickly will mean you end up heating the polish up too much and it will clump up and not work into the paint work.
Storry, if you're getting fed up with it taking ages to do, why don't you just do a couple of panels at a time? Bonnet and front wings one weeekend and doors the next etc. If you do it on consecutive weekends or relatively close together, you shouldn't have to redo the pre work and just hive it a quick wash.
