Almost any combination of soap (or detergent) and water will work. Certain brands of cleaner have their advocates. If you haven't already, go to the RV.net travel trailer forum and search on "trailer cleaning" and you'll be amazed at how much interest (and brand loyalty) this topic generates.
To my way of thinking, it's not the soap used but rather the technique of cleaning that's most important if you want to keep your unit's surface in good shape. One technique seems to be to apply concentrated cleaner to the RV and chemically dissolve the dirt, road gunk, and bugs away. Well, having spent a lot of money on my Sunline, I myself am not about to soak my unit's fiberglass with concentrated cleaner of any kind. The finish is tough, but it can be damaged.
Instead, I advocate using a combination of dilute cleaner (I agree that "Awesome" is a good choice) and some elbow grease. My technique goes like this: (1) Do an overall cleaning with dilute cleaner, plenty of water, and a deck brush. This gets off most dirt and leaves the stickier stuff. (2) Go over the unit again with a spray bottle of dilute cleaner and a thick towel for scrubbing. You'll get rid of the fresh road tar and most of the bugs. At the end of this step you'll only have the toughest spots of tar and most baked-on bugs remaining. (3) Go over the unit one last time with dilute spray-on cleaner and a Dobie pad (I recommend Dobie in particular. Other products may have scouring surfaces that will damage your unit's finish). Most of what's left will be located on the front (mostly bottom-half) and rear of the unit. Use the Dobie pad to lightly--and I emphasize lightly--buff the spots away. The point here is to use light physical pressure to remove the spots rather than trying to chemically dissolve them. Wash as often as needed and wax the unit (I don't know if you do this for aluminum) twice a year.
It's less work than it appears to be. Even after two dirty weeks in the wilds of Michigan's Upper Peninsula, I can completely clean my T-2499 in one morning. Unless the trailer is super-dirty, the last two steps involve walking around the unit and doing spot-cleaning.
Hope this helps.
2005 Sunline Solaris SE T-2499
2006 Chevy 2500HD D/A