Grubee is just a brand of the same engine that everyone buys- it means nothing. Don't buy a 49cc, cops don't know the difference between a 49cc and a 66/80cc (they cost the same)- just tell them it's a 49cc if you get stopped. I doubt they'll ship the whole thing off to CSI:Miami to forensically determine the truth!!
I'll tell you what they don't tell you. It takes approximately 6-10 hours to install the kit if everything goes right and then another 100+ hours of tinkering/get things perfect and then infinite amounts of time thereafter fixing things that break/stop working or fall off when you're riding.
If you're looking for an endless frustrating experience- you've found it!
But I still love it and would do it all over again- no I wouldn't.