Ultimate Hunter vs. Relentless Hunter on Rengar: Is the higher win rate misleading?

I’ve been looking at Rengar’s rune stats on Lolalytics, and I’ve noticed that Relentless Hunter has a higher win rate than Ultimate Hunter, but significantly fewer games played. Is this difference likely to be a statistical bias caused by the smaller sample size, or is Relentless Hunter genuinely the better option? Ultimate Hunter seems useful for getting more ultimate casts throughout the game, while Relentless Hunter offers more out-of-combat movement speed for roaming, map rotations and getting picks. For those of you who main Rengar in Diamond+ or higher, which rune do you think provides more value in practice?

If you had to choose one of these two runes every single game, regardless of the matchup or team composition, which one would you take and why? I’m particularly interested in whether Relentless Hunter’s higher win rate is reliable enough to justify picking it consistently, or whether Ultimate Hunter is the more consistent and reliable choice for climbing.