I practically grew up on Higgins Lake, at least during the summers... but I don't think I'd recommend anybody trying to get into there now.
I guess with so many of the lakefront owners dealing with financial problems downstate you may be able to pick up some lakefront property "cheap", but cheap on Higgins Lake is not like cheap anywhere else. You'll be looking upwards of $10k/ft of lakefront in most spots, with the cottages being 50+ years old.
Up until this last year it's been getting much, much busier (at least on the North end). This past year it's been down quite a bit, more like how it was 20 years ago, but I can't picture that lasting too long.
I agree it's the nicest lake in the state in terms of boating/swimming, nothing else I've been to is even close, but the price definitely reflects that. If you can afford it, and you can get up there enough to make that investment worth it, then by all means do it. But if you're just a typical downstater who'd like a place to put his boat in the water for a couple weekends a year, it'll be very expensive.
I'd mention the other
minor irritations, like the lakefront owners vs. the backlotters, and the swimmer's itch developing in the shallower areas over the past five years, but honestly they're not a big deal at all. All in all, Higgins is definitely deserving of a serious look for anyone who's looking at getting a place on a lake. There are many other options out there though.
Any lake where you have a perfectly sandy bottom you can see through 20 feet of crystal clear water is a good lake by me.

(Truthfully, growing up on this lake has spoiled me to all other lakes I've been to... they may be perfectly nice, but compared to Higgins they feel... "gross."

)