I traded in my 04 Suzuki LC1500 in for an 07 Vee, one short test ride and I was sold. We had an 08 Wee for the wife, and when my 07 was totaled, I replaced with a 2012 Wee. I just now sold it after 40,000 miles, and purchased a used 14 Vee this weekend. These are terrific bikes for most any kind of riding you could be interested in, excepting single track dirt, rocks, and soft sand, unless your skill level and accessories are up to it. For local commuting, day trips, traveling cross country, and fire roads, or even somewhat maintained dirt roads, etc, they are terrific. Lot's of riders get into some pretty gnarly stuff on these, but I like to keep things upright, easy, and clean, dent, scrape, and damage free. I've never been a dirt bike rider, and these are tall, heavy, and have lots of plastic and painted metal parts I just don't want all hammered up.
As for the 2012+ for the DL650, that is the year Suzuki made major changes to the motor, the body work, the electronic dash with trip computer, ambient temp gauge, digital speedo, etc, and gave it ABS. All good improvements, it was one of the factors in my buying the 650 when my 1000 got put down.
For the DL1000, they made similar changes in 2014, gave it ABS, Traction Control, new body work, dash, etc, along with changes to that motor. Also worth waiting for, it is why I sold my 650 and bought a 14 1K.
I can tell you, after just the 300 mile ride home yesterday, the Vee is a noticeably better bike, the suspension, brakes, motor, etc, all worth looking at, if it's in your budget. Especially, if you have a passenger now and again. Not to say the 650 can't carry two, it did fine with my wife and I, but I did miss that bigger motor, and the ability to pass on single lane highway, and I used that plenty on the 150 miles or so of it between Reno and Oregon yesterday.
Good luck in your search, there are some nice examples of 650's and 1000's out there, all accessorized with low miles, and good prices.