Pros: Speedy pickup, good build quality, good drag system
Cons: Wish it accommodated more line/backing
I've had the Battenkill Large Arbor in 5/6 size for about 2 years now, and I can't ever imagine switching back to a traditional-sized reel. When I use one of my friends' traditional reels now, I hate it. I feel like I'm working twice as hard and not picking up line fast enough. This might sound very petty if you've never used a large arbor, but once you try a it, you'll see what I mean.
Regarding build quality, I think I can best describe it by explaining how abusive to my reels. Unless I'm bank fishing, I almost always accidentally dip my reel into the water (both fresh and salt) while I'm fussing with my rod. A lot of times when I'm tying something on, I look down to see that I've reel pushed into mud or dirt. It's spent hours in the nasty water at the bottom of a drift boat. I leave it outside during dust squalls in the desert. When I'm done with it, I put (still wet/nasty) it into it's nice padded leather case and forget about it until my next trip. Through all of this, the reel still works like it did the first time out of the box.
The drag system on the 5/6 is straightforward and effective for trout. The strongest fish I've hooked with it is a 27-inch salmon, and it was barely manageable with the drag on the highest setting and me palming the reel - so it probably isn't the best for salmon. Then again, I probably shouldn't have been fishing for salmon with a 5 wt setup. I assume that Orvis equips the larger Battenkills with stronger drag settings for the saltwater crowd.
Swapping spools is also very straightforward.
My only real complaint with it is the depth of the arbor. The guy at the local fly shop machine-loaded my backing and 5 wt. floating line on the reel using 100 yards of backing. This leaves not enough room for the floating line. The result is that if I'm not careful to always level-load the fly line while fishing, the reel will jam when the fly line hits up against spool retainer. I'll simply have to use less backing, or use the new thinner backing that I've seen recently.
I paid $145 for the reel and $75 for the extra spool.