Thundertoss' show I'd also say was a success. A top 25, or even top 50, restriction not only limits the player pool, but also the capability of winning (which ought to reduce the player pool even more-so) As I was saying earlier, a top 25 GM vs a top 25 GM should be approximately 50/50 w/l ratio.
A broadened player pool would alleviate such a static w/l ratio, making winning more feasible. But I guess, in reality, this all comes down to the player's choice. Regardless of statistical inferences into winning, if top 25 GMs do show up to play, then it'll be a success.
I just know that if you messaged me with this, I'd say "yeah, yeah, totally, sure you're right $50 is better than just ladder!" Then you schedule a specific date, and half the people who said that have plans, forgot about it, or aren't online.
If you're getting the proper player base, then great! Producing content surrounding named NA pros can create that battleground we very much need; it can be a platform to build personalities, rivalries, back-stories for bigger events, etc. All of which is much harder when every other game consists of mid-level GM pros only 200 people on TL know about.