I have 4 system of tx rx evolution g2, and want something more powerful and professional than that, thinking to replace only receivers with something diversity and later to buy tx too, make it sense for you ? Someone suggested me to buy wisycom MCR42, 100 mw, diversity, and good sound,
have you any other opinion and advice?

Many systems use a 'coded' squelch which virtually makes using the TX from one brand unusable with a RX of another brand.
The RX and TX need to be of the same brand and often the same series to be fully compatible.

the seller guaranteed me that thos wysicom work with tx g2.

With coded squelch ON or OFF?

I am not prepared to run any systems that I use without coded squelch ON ...... to much RF rubbish out there these days.

the seller guaranteed me that thos wysicom work with tx g2.

You need to confirm this properly with WisyCom as the G2 uses Sennheiser's HDX noise reduction and the receiver needs to properly decode this.

So check properly with WisyCom and don't just rely on the seller.

WisyCom at IBC - ipsTV (http://vimeopro.com/ipstv/ipstv-at-ibc-2013/video/74644369)

Sennheiser G3 pocket receivers are diversity, of course.