on the plus side
You get less darkening.
Neither positive nor negative
Hop utilization changes so if you go for a full boil look at the corresponding All Grain kit, and use the hop amounts from there.
Maybe negative depending on your point of view
More volume makes it harder to chill. If you have have a good chiller, no big deal.
Need a propane burner? Can't use the kitchen stove any more?
It will definitely make you start wondering, "If I can do this, why don't I just go all grain" at which point you start thinking, cooler, grain mill, RIMS system...
Gear Aquisition Syndrome can kill relationships...