Only issue is money, and that I already got a Epm2.
But I will someday get the GM5 or perhaps the GM1 if I start enjoying screens. The only thing I don't like about the GM is the 1/50 sync speed for the flash.
But apart from that, they are a great camera line.
The GM1 is an amazing little camera. I take it with me mountain biking & hiking all the time. For an incredibly tiny kit the GM1 and the 9mm BCL are a good kit. I have the 14mm on it 75% of the time though.