The configuration of the Waves L2 UltraMaximizer is definitely a bit more in depth than the plug-in version but still isn't terribly hard to use. The main parameters found here are for threshold, output ceiling, attenuation, and release, and you can also adjust the volumes of each channel independently. There are more settings here but these are the main things to think about the L2. The manual might be a good thing to check out once or twice, but once you get into it, it won't be necessary.
The sound of the Waves L2 UltraMaximizer is quite awesome, as it makes what you put through it sound great right off the bat. When I was getting my last album mastered, the mastering engineer used this and showed me the difference between it on and off and also the difference between this and the plug-in, which is quite different. This can definitely add a bunch of clarity to your mixes and also makes it possible to dramatically increase the volume of your mixes. It's smoother than the plug-in and also gives you more options to work with.
While certainly more expensive than the plug-in versions, the Waves L2 UltraMaximizer is going to be worth it for the pro mastering engineer. It gives you options in sound and can definitely bring your home mixes up a few notches. I don't know what this would go for now as it's definitely on the older side since it came out before the L2 plug-in but after the L1 plug-in. If you can find a good deal on it, it's going to be worth it for those home studio engineers looking to take their studio and mixes to the next level.