Yes, the VL3 is kind of a slow plane. It’s my favourite for low level sightseeing, because it can go slow and not fall out of the sky. But getting it back up to speed takes a while.
The Rotax 915 iS mod gives it some pretty serious, but realistic kick, as the 915 is actually an engine option for that plane IRL. It can still do its slow and low, but will take off like a scalded cat when you firewall the throttle. But not at an unrealistic speed like the Vertigo.
That said, I tried the Vertigo, and it’s a ton of fun. An 850HP turoprop engine on what’s only slightly heavier than a paper airplane is pure insanity and unadulterated fun. But it’s about as realistic as an honest politician. They basically took the engine out of a TBM and put wings on it. lol