I was actually a major fan of the M5 when I performed a lot of animation and psychokinesis stunts a few years ago. Honestly, I don't think anything else really comes close to it in terms of PK effects. It's a great tool that can be used for a lot of different types of magic. Admittedly, I even used the M5 for various paid performances but I gradually stopped doing so. I personally stopped using the M5, but not because it's a subpar device. I stopped using it because I was just getting lazy making the required props for it. If your friend's willing to put in the required amount of practice and energy into making the M5 work, I don't see any reason why he shouldn't get it. Most of the negativity toward this device comes from close-minded individuals who don't like excessive gimmicks. The M5 admittedly does take some getting used to, but once you're familiar with it, you can perform some really great miracles.
I'd recommend it.
With that said, if you're looking for a cheaper alternative, I'd recommend looking into thread work. A lot of the material that can be done with the M5 can be duplicated with an ITR. This is what I currently use and I'm fully satisfied with the transition. Michael Ammar has some great thread DVDs and Mesika has a great product called the Spider Pen which is essentially a cleverly disguised ITR. These have been very valuable resources for me, and I love using them on a regular basis. Thread work does enable you to do more 'impromptu' work than the M5, and it's been more practical for me using in paid performances.
RS.