Mark, I do hope the search will be better – it’s hard to tell right now because there’s not much on there. I hate to say “it would be hard to make it worse than GG search…” 
Paying for Discourse feels less sustainable somehow, but I think there’s a core of contributors who are making a move to build momentum on TW, and paying for a tool to help your community communicate, support each other, and onboard new users makes a lot of sense through that lens. It’s a risk, but it’s a move.
With GG, I’m not 100% sure Google won’t just pull the plug sometime within 2-3 years.