What do I like best? As odd as it may sound, the fact that I'll cut off every single thread in it, run them out, and rethread with aplomb. Changing threads is my previous machine (20 year-old 4 thread Juki) was an undertaking that I did with trepidation, and felt I deserved a medal afterward, on the Evolution, it is no big deal. This leads me to try new things, not use gray thread on everything, and enjoy sewing much more.
I enjoy the feeling of the machine, it seems nice and strong. In my search for a new serger, many that I tried seemed kind of weak and light, with all it's quirks my Juki had always felt very firm and substantial, and I was searching for that. The Evolution doesn't feel as if I might break something in the normal course of use, or that needs to handled like a crystal vase.
All of the things it does, I never knew there were so many options. It's been great fun threading up the different combinations and seeing how they stitch out. Will I ever really use them all? Probably not, but there is something very nice about feeling like you have all the options. And that leads to..
..the coverstitch. This is my first experience with this feature, and once I got comfortable with it, I love it. There was a bit of a learning curve (meaning I really messed things up at first), but now conversion is easy. I am just thrilled with being able to finish things so nicely. I don't have anything to compare it with, so...
The feet. I bought my machine used, and it came with the 6 foot package. I also got the Curve and Cover/Chain Stitch feet, as well as the Fabric Guide and 36mm Double Fold Bias Binder. So far I've used the elastic foot with good success, I'm not sure I'll use the rest of the feet in the 6 foot package much, as most of them are about beading, piping, ruffling, and lace. But they are good to have, I suppose.
I highly recommend the Curve foot. The standard foot on the machine is very large and can be hard to get around any curve, or even see what you are doing. the Cover/Chainstitch foot is nice, but I think you could get along about as well with the curve foot. I'll say the same for the Fabric Guide, it's nice, but after working with the machine a bit, I don't think I need it. The Binder works surprisingly easily, and does a great job. I thought it would much more complicated than it is. It is worth having.
I haven't found it difficult to change needles of thread them. I have found it makes it easier if I remove the presser foot first. It snaps off and on, so it's not a bother.
Wave stitch, nice and cute, but I don't see myself using it a whole lot. I certainly wouldn't consider it's availability as any kind of measure for buying this machine or not. It's a fun add-on, that's all.
The things I don't like are few. Most of all, it comes down to placement of some of the controls. The differential feed lever is ridiculously large and in a very bad spot for me. I'm not sure if it's because I'm a lefty, but I seem to end up bumping it somehow and having those "What the heck is wrong?" moments.
The rest of my troubles pretty much amount to rookie mistakes and just getting used to, and learning to use, the machine, but it seems some of the less important controls (wave stitch) are a bit too large and some of the essential ones are a bit small and hard to reach.
I wasn't crazy about the price. But if it serves me as well as my last one, it's worth it.
All in all, I'm very happy with this machine.