To the OP: Do not give up on 6013 just yet. Although I am not a huge fan of 6013 it is still useful for some applications. (like thin sheet metal when no wire feeder is available)
Really Every welding machine (even expensive ones) have brands of rods that they burn better than others. Your machine is limited in some aspects in that it is AC only and it also has tapped amp settings instead of infinitely adjustable amp settings, but that does not mean it still can not work very well. The key is finding the brand of a particular rod type and size that actually burns well on a setting that you actually have on your welder. Brand A may run like crap, but Brand B might run perfectly. It might even go as far as Brand A in 3/32" diameter but Brand B in 1/8" diameter within a rod type. Once you find one you like then that rod is a keeper for your machine. I always buy small packs to test then, once I find one I like then purchase the more economical size. Another thing that can also confuse the situation is that even Lincoln and Hobart often make 2 to 3 grades of a rod type. Some grades within a brand are just not suitable for the buzzbox class of machine.
7014 rod might be the one rod that might actually run better on AC as compared to DC. I love 7014 too.
I started out with a Lincoln AC buzzbox. It was a great welder and I would still have it had I not stumbled into a bargain on my Miller buzzbox. 6011, 6013, and 7014 were always my go to rods on the Lincoln.
While I have a Miller thunderbolt AC/DC now (The Lincoln was better on the AC side of things in my opinion). I decided to keep the Miller because it did have DC. Had it been an AC only unit then I would have kept the Lincoln. 6011, 6013, and 7014 are still my go to rods on the Miller even with the DC capability - although some of my brand preferences have changed slightly with Miller (again every machine has brands it likes better than others).
For me: I hardly ever fool with 7018 as I do not want the rod oven storage hassles with it, but if I did feel I absolutely had to have it for project then I would go 7018AC. 7018AC will also burn on DC and is almost always a better choice for the buzzbox class of welding machine even if you have DC capability. With an AC only machine it is certainly the best choice. Now which brand? That will be up to you to determine - LOL. (And do remember that any 7018 or 7018AC can be very finicky and difficult to run if it has drawn moisture. Guys that weld a lot and go through rod quickly hardly ever see it though even if they do not store it properly. Occasional hobby welders where rods stay on the shelf for months and even years like in my case do see it though especially when your shop is an ole damp barn).