My criteria is mainly looking at fundamentals of the network and likeliness of success, but also looking at the opportunity as an investor so consider technicals, market cap etc.
I own a bit of all 3 but have only been a buyer for about 1-2 months with most money not going in until more recently. I own the least Storj, mainly just because charts looked bad so I thought I could buy cheaper. I just listened to the December town hall meeting for the Storj project and they sound like they have their stuff together and am moving more funds here.