That old '87 Suzuki was a fantastic machine. It was waaaaay ahead of it's time. The hight/low/super low range transmission was unbreakable and could put the power to the ground. Even with it's small (by today's standards) 250cc engine, that machine, if tied to a tree would dig itself into the ground. The suspension was also in a league of it's own. The comfort of ride was excellent on all but the nastiest of trails.
I had that machine from 1987 to 2007 and other than the brakes, it was an excellent machine. In 2006, I bought a 500cc liquid cooled Suzuki powered Arctic Cat automatic, just in time for the hunting season. I have to say that I was sorely disappointed with how much noise it made. I couldn't stand it. The engine would rev to 3000 rpm just to move along at 10 mph. The old Suzuki would do that speed at less than half the engine rpm and was so quiet, I could hear birds chirping when riding it. I still had the Suzuki and found that I rode it more that season than the new Cat. I came to the conclusion that I hated automatic transmissions for hunting. Great for working around the camp hauling boats, firewood, ice fishing and doing other chores but stealth was certainly not it's strong suit.
In the spring of 2007, I sold the old Suzuki to a friend who was in need of a machine. I practically gave it to him. My unhappy experience with the auto transmission taught me that the next machine will have a manual trans. Accordingly, in March of 2007, I bought another 500cc Suzuki powered Cat but with a manual. What a difference. It was like night and day. Now I have the manual that I use primarily for hunting and the auto for flogging around the camp. There are very few ATVs being made these days with a manual transmission by the way.
I've always had two machines around the camp so that I had something for guests to use. The auto can be ridden by a chimp so when I have company, they get the auto and I take the manual.
I have to say that I'm disappointed with the physical size of the new machines. They're huge by comparison to the LTF4WD. Trails that I used to scoot around on with the Suzuki were too narrow for the Cats. I have to pack a chainsaw with me now to take out the odd stump or log or clump of tag alder. The big machines are not nearly as nimble as the Suzuki either. I could put more riding time in on the Suzuki with less effort that with the Cats. And, the thing is, the bigger machines can't go everywhere the Suzuki can, but the Cats can't go everywhere the Suzuki can. So, in some respects, I went down in machine capability.
The new machines are heavier and more powerful which make them better at doing a lot of things like towing, plowing snow etc. but they do give up some versatility.
That 300 you have is great ATV. Treat it well. If you do the things that I do with an ATV, you will not be as happy with today's offerings if you decide to replace it.