I had a 6000D. Purchased it new. On about my third trip with it, I hooked up a striper that must have been at least 50 lbs. He kept pulling drag and I kept tightening the drag. I finally got the drag so tight, that I wasn't LOOSING MUCH, on this fish. Then I heard a noise comming from the reel. Then, the reel just tore apart inside. I couldn't reel the fish, so I cut the line. I sent the reel back to Shimano and they sent me a new 8000D, that I promptly sold.
I told a friend of mine, who repairs reels professionally about my experience. He wasn't surprised. He told me, to put it mildly, they ARE NOT QUALITY REELS! He further informed me that no matter how tight the drag, those gears should be able to handle it. The Thunnus Cl series is also a reel not to buy according to this reel repairman. I asked him to recommend a bait-runner I could use for striper or drum. He recommended the Diawa Sealine Black bri 4500. I purchased one and love it. In size, it is comparable to the old Shimano 4500. It is smooth as silk and the long spool allows for longer casts.:thumbsup: It retails for about $150.00. Max drag is 33 lbs. More than any D series Shimano, even the 12000. Daiwa also backs their products much better than Shimano. This repairman needed a part for a Daiwa that hasn't been manufactured in over 30 years. He called Daiwa and got it. That won't happen with Shimano, according to this repairman.
The old 3500, 4500 and 6500 Shimanos were fine reels. The only problem you might encounter not is finding parts if you have a problem with it.