I have been having problems hearing the rest of the band when playing live and had tried a number of things to resolve it.
The rolls personal amp has solved all the issues not only can I hear perfectly but I can control the volume on my head mike when not singing. Build and sound quality is excellent and its compact enough to be easily stored in a tool box. Highly recommended.
We have a set of these, and some Rolls PM351 boxes and a couple of the PS16 boxes. Each person can independently add more of their own mic (and with the PM351, mic and instrument) to whatever monitor mix is available. You could build a decent in-ear monitor system for a whole band with just these and a FOH feed, even better if you can send a couple of monitor mixes from the mixing console. Users and sound techs need to know there is no limiter built in to these, so to be careful when plugging/unplugging mics etc.