I was recently given this reel. Japanese made, standard size round casting reel. I gave it a good cleaning, and lube job. This one has thumbar casting,  and magnetic cast control. Seems smooth and decent quality. Not a lot of info out there on these reels. I haven't been a huge Qauntum fan. Anyone have experience with these? Good or bad?

I used to have a Big Iron on a flathead rod, I regret selling it. 

They were a decent entry level round reel, kind of like the Shimano Corsair of the same time frame
(late 90's), I believe.  I doubt it will be turning any heads, but if you need a solid performing round reel, I am sure it has some life left in it, or it would make a great gift for a teenager just learning to fish and use casting gear.

I still have a working IR3 from the early 90s.  I haven't used it in years, but it still works.  Built like a tank.

I have a Quantum IR300C (iron series). I purchased it on clearance at a kmart around here back around '03 or so. It was my first baitcaster. I still own it and fish it today. Earlier this year I tore it down and gave it a thorough cleaning (the thing was a mess inside). Since the cleaning and re-lubing its actually really smooth and easy to fish. I personally think it seems to have a solid build quality with an all aluminum frame and it was actually made in Japan.

This was my first casting reel. They are of decent build quality. Mine is long retired and looks a little beat up... but it still works. 

I've got the iron baitcaster that was replaced with the monster reel, I use it for pike and musky and love the thing. Handles big baits very very well.

Hey does anyone know the best weight of line to use on a Quantum Iron ir3 reel i only do trout fishing with this reel but i just got it and don't know the best weight of line?

I still have a few IR4's on my catfish rods. I reckon they'll likely outlive me. As J Francho said, built like a tank. Great for pulling big cats out of log jams.