I don't consider an autofeeder optional. They remove the human element from feeding, which in my case is a good thing. I'm an inherently forgetful person, and I also work full-time. I don't have the time or the mindset to feed the tank multiple times a day, but a feeder means that the tank doesn't depend on me doing so.
There's only two that I think are worth buying - the Eheim feeder (budget option) and the Avast Plank (the correct option). Eheim is reliable and affordable, but the way it measures out food isn't terribly precise and it's really limited to prepared foods (flakes and pellets). If you can't afford the Plank it'll get the job done, and it's also battery-powered and entirely self-contained.
Plank dispenses via a worm screw, so you can feed exactly as much as you want, as precisely as your timer will allow. The feeding tube allows for rehydration of freeze-dried food, which opens up freeze-dried as a realistic option - without something like the feeding tube, freeze-dried food often just goes straight down the overflow. The hopper is massive - I can store multiple weeks of food in there, and I just need to remember to mix up my blend of food every so often and refill it when it gets low.
The downside of the Plank is that figuring out the appropriate amount to feed is a matter of trial and error, and it's easy to dramatically overfeed your tank with it. On top of that, it has no integrated control mechanism - when it has power, it dispenses food, so you have to have some external way to control it. It works great with an Apex or a Hydros, as you can program those to have the outlet on for an arbitrary length of time. Otherwise, you're limited to whatever your timer offers. A minute of dispensing is quite a bit of food that can easily spike your nutrients if you don't have the fish/CUC population to consume it all. It's also quite a large unit, and the feeding tube means you have to accommodate it in some way if you have a lid on your tank.
