Looking at the B website there seems to be only less than a 1/2 inch (maybe 1/4) difference in size. Is the website wrong?

No, there really isn't much size difference between the two. W/the Compact you get a fuller grip, greater mag capacity and the rotating bbl action which, IMHO, does a good job of redirecting recoil so there's more push but less snap (the subcompact has the typical tilt-bbl action).
The Compact comes w/an ambidextrous slide release & safety/decocker (I'm not a fan of slide-mounted safety/decockers so I had mine easily converted to G-style decocker-only).
Biggest downside to the Compact is that the front sight has a proprietary width so std PX4 aftermarket night sights for the fullsize & subcompact won't fit, requiring a custom install by Tool Tech (they drill the factory sights to install Trijicon tritium vials, pricey but worth it).
The PX4 Compact is now my EDC, primarily due to the recoil impulse which makes for faster followup shots for me (YMMV).
Tomac

I prefer the sub. The slight difference in size is enough to help with the printing problem.

Personally, I like the compact. Like the Glock 19, it's a perfect fit for my relatively small hands. Enough for a full grip, no pinky hanging off or a worthless floorplate that adds length but no capacity.

15/12 rounds of 9mm/40 cal. More than enough, considering the small size. Magazines are expensive at $35 per, but everything Beretta makes is expensive.

The rotating barrel design is ingenious, as it reduces muzzle flip a great deal. The tiny subcompacts are very annoying in that regard, as there isn't enough of a grip to get a good hold on it to mitigate the recoil, especially with the snappy 40.