Nothing - but T20 in this country isn't, currently, exploitable in relation to franchises, player auctions and council TV access .
Yeah the Blast is stuck behind Sky's paywall but I don't believe Sky have monopoly rights to the format! Hence why the BBC signed up to it when it was a T20 competition. I doubt they'd sign up to something they wouldn't be able to broadcast. You can surely broadcast a completion on exactly the same basis as the Hundred that's a T20. That's what puzzles me at this point.
If T20 had kept to the process of time allocation (i.e. complete the overs by a certain time otherwise incur a penalty) then that would be one of the things I would prefer. The Hundred does that, and it puts the pressure on the fielding side to stop faffing around with field settings after every ball towards the end of the Innings otherwise they lose a boundary fielder to the inner circle.
Also with the reduction of 20 balls per side (40 per match) it does allow sufficient time for two matches to be played at the same ground on the same day (Womans and Mens) without the possibility of it taking too long - particularly it should also help promote the Womens game more to a newer audience. I always felt that the T20 Semi 1 - Semi 2 - Final day was too long plus fitting four teams worth of supporters into a stadium for two teams of supporters to have the possibility to leave after the Semis was counterproductive.
Yeah the administrators have been ridiculously lax on slow over rates for a while now. Aren't we down to some crackers like 12 or 13 overs an hour in Tests? Though it seems odd to just give up and knock balls out of the match rather than get to grips with the issue properly!
I will grant you though that it's great that the women's game is getting more exposure and a proper professional tournament. Though the issue of double headers is surely solved by pushing back the start of the women's game to maybe 2pm?
I've always enjoyed finals day but on the TV. You're right it must be an incredibly long day at the ground. Plus there's an element of disadvantage for the team that wins the 1st semi as they've got get themselves going again after a lengthy break unlike the team which wins the 2nd semi.
But, again, these are potential issues with the format of the Blast not with T20 itself...