Yup....you're in the right place.

You might also post this in the 2009+ F-150 forum when you get a chance.
On to your question......
There are a few differences between the Tow Package and the Max Tow Package. Here are the contents of each according to the 2011 F-150 Order Guide:
TRAILER TOW PACKAGE (535)
Usage: Required for towing over 5,000 lbs.
Availability:
Standard on FX2/FX4 and Lariat
Optional on XL, STX and XLT
Includes:
Class IV trailer hitch receiver
7-pin wiring harness
Upgraded radiator
Auxiliary transmission oil cooler
SelectShift Transmission
MAX TRAILER TOW PACKAGE MANUAL MIRROR (60M)
Availability:
Optional on XL Regular and SuperCab
Not Available with:
126" wheelbase
Power Equipment Group (85A)
Max Trailer Tow Package (60P)
Requires:
3.5L EcoBoost Engine (99T)
3.73 LS rear-axle ratio
Heavy-Duty Payload Pkg. (627)
XL requires Fog Lamps (595) with XL D้cor Group (86D)
Includes:
Upgraded rear bumper
Class IV trailer hitch receiver
7-pin wiring harness
Upgraded radiator
Auxiliary transmission oil cooler
Trailer Brake Control
SelectShift Transmission
Side mirrors, black manual telescoping trailer tow w/manual glass
MAX TRAILER TOW PACKAGE POWER MIRROR (60P)
Availability:
Optional on XL Regular and SuperCab, XLT and FX2/FX4
Not Available with:
126" wheelbase
Max Trailer Tow Package (60M)
XLT SuperCab 145" wheelbase with P235/75R17 BSW A/T (T7B),
L245/75R17E BSW A/T (T7E) or P255/65R17 OWL A/S (T73)
XLT SuperCrew with P255/65R17 OWL A/S (T73) or L245/75R17E
BSW A/T (T7E)
Requires:
3.5L EcoBoost Engine (99T)
3.73 LS rear-axle ratio (XL, XLT and FX2)
3.73 electronic-locking differential axle (XLT w/Off-Road Pkg. 55A and
FX4)
XL requires Fog Lamps (595), XL D้cor Group (86D) and Power
Equipment Group (85A)
XL and XLT Regular Cab requires Heavy-Duty Payload Pkg. (627)
Includes:
Upgraded rear bumper
Class IV trailer hitch receiver
7-pin wiring harness
Upgraded radiator
Auxiliary transmission oil cooler
Trailer Brake Control
SelectShift Transmission
Side Mirrors, black manual telescoping trailer tow w/power glass
(includes heat, turn signal & puddle lamps)
Memory feature included on side mirrors when order with FX Luxury
Package (55F)
MAX TRAILER TOW PACKAGE POWER, CHROME
MIRROR (60C)
Availability:
Optional on Lariat, King Ranchฎ and Platinum
Requires:
3.5L EcoBoost Engine (99T) or 6.2L V8 (996)
6.2L V8 on Lariat and Platinum also requires SuperCrew 145" WB
3.73 LS rear-axle ratio
3.73 electronic-locking differential axle (Lariat or King Ranchฎ w/Off-
Road Pkg. 55A)
Includes:
Upgraded rear bumper
Class IV trailer hitch receiver
7-pin wiring harness
Upgraded radiator
Auxiliary transmission oil cooler
Trailer Brake Control
Side Mirrors, Manual Telescoping Trailer Tow w/Power Glass (includes
heat, memory, turn signal & puddle lamps & Chrome Skull Caps)
According to the order guide, there are three versions of the Max Trailer Tow Package which are differentiated by minimal content changes and the models upon which each is available.
The presence of the OEM Trailer Brake Controller on its own doesn't mean it definitely has the Max Trailer Tow Package. The controller is a stand alone option and is available with the Towing Package as well.
That said, one way to tell quickly is that the trucks with the Max Trailer Tow Package will all have the towing mirrors like these:
If the truck has the standard mirrors, it doesn't have the Max Tow Package. (Unless someone changed them out after they bought it)
Hope this helps.