I like this one because the battery charger is built in.
This is one of my club rigs. Simple, effective and complete. I run two of the Shure GLXD-4 units, either switchable with an A/B box for two separate basses, or one for a wireless vocal mic. The little "D" shaped ports are where the rechargeable battery loads for charging. To the left of the port is the volume control, useful to quickly set a constant input between different basses, such as an active and passive bass. My passive bass volume is "+10 db" and my active basses I set at "-5 db" on the screen. Each button push is one db change. There is also a meter that shows the input and an upper bar graph that reads "OD" for over drive, which lets you know you are exceeding the clean input of the unit. After playing a bit I found where I can keep the bass giving a good signal, but not over driving and distorting the signal. This is a nice touch to keep your bass input at the same leve regardless of bass so I don't have to change amp or effect settings down the line. To the left of that is the display screen. The screen will let you know hours and minutes left on the batteries. I normally pop them in after sound check for an hour, which tops them off. I rarely run under 10 hours of run time on the batteries. It also displays the input level, channel and sub group the wireless is running in. It's dual diversity as are most, so it's always got a backup up in case one gets interference.
To the left of that are buttons for scan and manually setting freqs/sub groups, and a blue transmitter light.
Occasionally on heavy use band width areas, such as major cities (Chicago, East coast, Dallas, Denver, etc.) or on busy stages, I've noticed that after everything being good at sound check, when show time rolls around, the light might blink a little, telling me the freq I'm on is overloaded and I'm going to experience a drop out. I just push the scan button, and the system automatically finds a clean freq group in about three seconds. I actually had this happen playing one night in down town Chicago. I got a flicker going, waited for a break in the song, pushed the button, and by the time I was ready to hit the next note I was in a clean freq group. I've never had to change more than once after I've pushed the button.
I put over 600 shows on these in two years, and they are still going strong without an issue at all. The batteries are a strong as the day I got them, without any memory forming or any other issues. I normally charge the batteries between sound check and show time, often it's less than an hour. I can usually top them off with that much charge. I seldom run under 10 hours of runtime on the batteries. I did run a battery all the way down once, to see how close the estimated time left on the battery was to the display, and it was actually quite close.
I was going to get a higher level (read more expensive) unit, but there is no reason to replace them. They seem to be a very well thought out system, sturdy and packed with all the details I will ever need for gigging in clubs/pro stages. After three years, the batteries have more than paid off the system by never having to buy a battery.
If you are looking for a great club rig, with the ability to be used on bigger pro stages, this system is tailor made for that.
No, I'm not endorsing this or anything along those lines. Just a more then happy customer.