Speed difference on supergrok vs supergrok plus?

I'm using a SuperGrok, getting into the swing of it.

I see supergrok says "lightning-fast replies" on the pricing page (where supergrok doesn't) - can anyone confirm if it's noticeably faster?

Currently it seems to take maybe 5-10 seconds for short replies so I'm curious if it's more like 1-3 seconds or something for the higher tier.