[Trackrash]

Originally Posted by Evan Fullerton

VW bugs and 901s use the same syncro technology and basic architecture but they shift better because the gears are smaller and lighter,

Not true. The 901s and 915s use the ZF style synchros. The VW Bugs use the Borg warner brass rings.

I have a warmed up '67 Bug, in which I have a built (by me) heavy duty custom trans. I also have a modded, by me, 915 in my 911. The only thing the VW box can do that the 915 can't is to speed shift from first to second gear. In normal driving not a world of difference.

As Matt says, and others have mentioned, there are subtle differences in the parts of these 915s that can make a huge difference in shifting.

You should find a 911 with a good shifting 915 to compare. It may be that your rebuild needs to be rebuilt.