Both Wager and Bookie seem ahead in development, that's the main reason why i look at them first. I do agree with the point that the ethereum network might be an issue. Both BETR and XBP are projects I can get behind as a more serious sports bettor. BETR more than the others seem to understand what it's about and are in the asian market which is huge. They also have the option open to move to EOS if Ethereum development doesn't improve. I already use something similar to what Blitzpredict is working on and it's a concept that really makes a huge difference for anyone who is serious about betting (the big money).
I'm not sold on the 'prediction market' concept and the other project primary seem ways for creators to make money without them really offering benefits over how sports betting works now. I believe better odds than what is available on the market right now (pinnacle / betfair/ matchbook / sbo / ibc / isn ) is what will make a project successful as long as everything works properly and is safe.
great incite, yes better odds is quite some incentive ha. I will definitely look more into BETR and Blitzpredict when I have more time.