1st Edition AD&D game I'm running, I'm also currently running a Pathfinder game that started as a D&D 3.0 game back in May of 2001.
I like Pathfinder as a system, even though it does get pretty fiddly with the rules. And don't get me wrong. There are a lot of rules in Pathfinder. Each class has dozens of options you can select as a player to build exactly the type of character you want to play. But, they are just that: options. You don't want 'em? Don't use 'em. Basically, they're like any RPG. Use what you want, and forget the rest.
One of the things that I really like about how Pathfinder operates is their willingness to playtest things with their community before they go to press. That way, the large majority of the kinks are worked out, and you get a much more superior product. It also makes it cool to get kind of a full-version "sneak preview" of things that are coming out later.
As a case in point, I direct you to the Ultimate Combat Playtest: Round 2 (Gunslinger) PDF, which you can download for free on the Paizo website. Ultimate Combat is a book that will be coming out later in the year, and it includes three new classes: Samurai, Ninja, and Gunslinger. A few weeks ago, they put the write-up for all three characters online for free and asked players to use them in their games and then post back on their message boards what they did and didn't like about them.
The Gunslinger class got the most feedback, and a lot of it was pretty critical. Some people don't like the concept of mixing firearms and magic, but really, this class is not for them. But a lot of people had some really interesting things to say about the class, including one guy who basically said the best Gunslinger build was to take 1st level as a Gunslinger, immediately sell the free firearms that come as part of the class features, buy a bow with a +6 strength modifier, and then progress as a straight fighter for the rest of your career. There was a little more to it than that, but the playtester caught a pretty fundamental flaw in the design of the class.
So, Paizo actually went back and basically rebuilt the class from scratch to address the open playtest concerns, and revised the class again. And now they're asking for feedback on this revised class.
I think it's awesome that Paizo allows these open playtests and doesn't keep things secret until they come out with something. It gives everyone a chance to feel like they're contributing to the game in their own way.
And, for those of you who don't play Pathfinder but only play earlier versions of the game, there's still stuff in here for you. As I've been saying a lot lately, an RPG is an RPG. It's really the ideas that are key, not the mechanics. Blackmoor definitely had firearms in it as I recall, and there were firearms rules in the 1st Edition Dungeon Master's Guide. This free write-up of the revised Gunslinger class includes a side-bar discussion on ideas of how to integrate firearms into a fantasy campaign, and the various technology levels you can apply (firearms are rare, firearms are just emerging, etc.). There's also content regarding various different types of firearms from early primitive types all the way through revolvers. And there's some great imaginative stuff regarding spells and magic items that apply to firearms. Even if I weren't playing Pathfinder, I'd be able to find some things in here to use in whatever system I do use.
I hope you check it out. Who knows? You may find other stuff on the Paizo website that interests you.