I agree with MJHKNIVES's comments regarding sawteeth. Sure, in a survival situation they might be moderately useful, but for the other 99.999% of your life, they're a PITA.
On the Model 16 you're interested in, check the spacing on the finger grooves. I had the Micarta between the third finger and pinky removed on my #14 (same grip) because it didn't fit right; once that was done it was a much better fit. The #27 will be a nice knife if you prefer that blade shape, I prefer the #5. Purely personal choice.
While we're discussing personal choices, when I think of Randall, I think tool steel. They sell a lot of stainless, but I can get stainless from lots of knifemakers and I actually know which stainless steel I'm getting from Benchmade et al. But one thing RMK does extremely well is forged tool steel. But if you need stainless (saltwater ops etc) go with stainless.
Personal preference (all tool steel):
** #14 (w/o teeth) I bought mine when I was on active duty and had it parkerized (on recommendation of a Marine on the staff). Great knife, the tool steel holds a keen edge a long time; you just need to get past destroying the collector value. It's been around the world on Uncle Sam's nickel.
** #1-7 Micarta is a classic design and you need at least one.
** #5-6 is a very useful useful blade and a great size for general use/utilty. Bradford Angier's mods were well thought out and functional -- mine is very similar.
** I just picked up an RMK #1-7 in Stag -- very nice knife, but I wouldn't take it camping, it's just too pretty

YMMV