It's not a favorite but it's nice enough for others to use. I imagine it's a name a fashionable couple would choose for their son. It's not trendy but definitely hip in my opinion. Personally I prefer
Jesper and
Casper.
I've actually met a little
Jasper. There's a little boy (almost 2) at the day care center where I work named
Jasper. His six-year-old sister is named
Io.
My favorite combo from your list based on flow is
Jasper Montgomery but based on middle name choice I prefer
Jasper Joseph and
Jasper Charles.