Ive only seen one "crate" vw motor purchased and installed by a local VW shop years ago.
The guy had ordered a pre-built and tested motor from a VW engine seller. The shop installed it, and they spent the better part of the day trying to get it tuned right. Ill never forget the smell of a new VW motor getting "broken in" No pun there

. But it smelled like hot metal. I figure it was probably set too lean or something, but I know they spent one hell of a long time just trying to get the Pre-run, Pre-tested motor to run right.
For me personally, I like the simplicity of a motor that manages itself, and tells you whats wrong, when it goes wrong (before damage occurs usually). Bugs are fun, no arguing that,..
For me in the end it was always the hassle of constantly having to be under, wrenching on them that did them in for me. The Subaru option gives that practicality to everyday use, without the need for carrying around a tool kit to the VW chassis, Something it really needs. Increased power, reliability, tons of spares, tons of performance upgrades,... the list goes on... and on,... and on...
A Subaru transplant can be done often for less than $2500 including the mount, adapter, and radiator. A ton of JDM engines are easy to get with less than 40-50K miles on them. Harness, ECU and everything ready to go... The flipped diff kit isnt necessary as seen in Bretts build. It was an option I chose. You could use your stock VW tranny if you like...