The vibrating at idle 4-banger thing seems to be hit/miss amongst all makes/models.
Most GM Ecotec powered vehicles I've driven are very smooth at idle, yet the 1.8L in my Mother's 2008 Pontiac Vibe shakes like a popcorn popper.
I recall the 2.5L in my 1997 Wrangler being rough, but that's a beast of another color.
My Subaru 2.5 idles very smooth, but isn't an I4.