I was on McDougall for 3 days this past June.  I spent one full day paddling and fishing it pretty hard, and did some morning or evening fishing the other 2 days.
My take on McDougall:  It has a lot of smallies.  Those smallmouth varied from just bigger than my Rapala, to my personal best 19.5".  It also has lots of 30" plus Northerns.  Very fun!  I bet I caught 20 over 30".  Biggest was 33" and 13 lbs or so.  The cherry on the top is that the lake has Lake trout.  I caught two in succession while trolling across the center of the lake.  That was after catching a couple 17" bass in the same area.
I did a day trip from there to see the pictograph on Montgomery Lake, about 20 miles that day.
Only real negatives were the site was exposed to wind and no walleye. 
I could give more detail on the areas I hit fish if you are interested.