Would be low-medium for me.
Novelty of big numbers has warn off imo. The gap feels smaller on low-medium servers.
e.g. You're 35. Highest = 45. 10 levels = doesnt feel too bad, and by the time you're 45, they'll only be like 46/47.
Instead of
You're 100, highest = 270. Bet leveling 170 times...