Pros: 200 watts, Wire beaters, Soft-grip handle, Comes with spatula attachment
Cons: Heavy (causing your wrist to tire)
I've had my MX55 hand mixer for about three years now. I admit, I don't use it more than a few times a month, but for the occasional cook, such as myself, this mixer works great.
Description: 200 watts of power, also includes a "power boost" feature, which provides an extra blast of power at any speed. There are 5 speeds, and the highest speed is very fast! I pretty much only use the bottom two speeds. The handle is soft-grip, so it feels comfortable in your hand.
There is also a spatula attachment, which continuously scrapes the bowl as you mix. The spatula attachment is flimsy plastic though, and can easily be lost at the bottom of the dishwasher (yes, I speak from experience). In order to make the attachment work, you position the mixer so that the spatula attachment is against the side of the bowl, so it can scrape as you mix. This way you don't have to have a second hand scraping with a spatula while you have the mixer in the other hand. It is a handy little addition, but to be honest, I always forget that I have it and usually end up scraping the bowl by hand anyway.
The beaters release pretty easily (but not too easily). There is a button at the top - you push down on the button to release the beaters. I once had a mixer that would spontaneously release the beaters, even if you didn't push on the release button! I've never had that problem with this mixer, thank goodness. The mechanism for releasing the beaters seems pretty well-made, and you've got to press fairly hard to make them release - so I don't think they'd ever come unreleased when you don't want them too.
Pros: You really can't beat 200 watts of power for a hand mixer in this price range. Granted, you may never need that kind of power from your hand mixer, but it's nice to that the thing isn't going to die from lack of wattage midway through mixing your Thanksgiving mashed potatoes! The wire beaters on this mixer are wonderful. It's kind of hard to explain, but some beaters are flattened, so batter sticks to the flat portions. These beaters are rounded, so less batter sticks to them. Another pro is the soft-grip handle. It allows your hand to grip onto the handle, and not slide around as the mixer is mixing.
Cons: The biggest con is that this mixer is just plain heavy! (I guess this is to be expected from the fact that its 200 watts?) I find that my wrist tires easily from holding the mixer upright. As stated earlier, the spatula attachment isn't that great, but it has come in handy a few times for me.
Also, I'd like to say that Black & Decker makes a few different models of blender that match the color scheme of this hand mixer. (I have the BL550). Granted, most of the time the hand mixer is in a drawer and not out on the counter, but if you like your appliances to match, keep this in mind.