My recent gearbox swop can only be described as exceptional.
Kept up to date throughout the build stage, and numerous texts with advice and recommendations on what parts to get, the date was set for the swop out of my standard Rev 3 LSD box and my new modified taller drive box.
Old box came out easy enough, but then we noticed a heavy worn clutch and flywheel.
This meant having to leave the car at the workshop whilst new parts were procured.I was offered Nathan's own personal car for me to use for 4 days whilst the new clutch, flywheel and gearbox was fitted.
Not talking any old car here....a Nissan Skyline none the less! 
Picked car up on Friday 14th May after Nathan had given her a test drive and can honestly report that the car drives like new.
Exceptional service by an exceptional company.
Thanks again Nathan.
More info on the results of the taller drive mod can be found here:
http://www.imoc.co.uk/forums/viewtopic.php?t=135421
And a general discussion around it, including the busted flywheel, here:
http://www.imoc.co.uk/forums/viewtopic.php?t=135158