You'd like to know what other reasonable contenders there are. The whole scene is very speculative at the moment - the technology clearly has huge potential, bu

You'd like to know what other reasonable contenders there are. The whole scene is very speculative at the moment - the technology clearly has huge potential, but its immature and hasn't solved some key problems like scalability and UX. Apart from the 3 you've mentioned I would suggest you could look at some of the projects that have recently launched ICOs (Initial Coin Offerings). Many of these are plain stupid, and all of them are raising funds for tech that doesn't exist yet, but if that doesn't put you off take a look at the AEternity project (https://www.aeternity.com https://www.aeternity.com), and NIMIQ (https://nimiq.com/ https://nimiq.com/). They look like two of the better ones to me. Ripple might also be worth investigating.