We recently purchased a pair of the BT-12 tilters from Nimrod, and they are quite possibly my favorite piece of gear. They make an incredible difference, especially for the smaller bar gigs that we run during the colder months.
I was impressed with the entire experience - from ordering to delivery to day-to-day use. I was quite honestly surprised by how fast they arrived - I think it took 3-4 days for them to land in my hands here in the US.
Even the foam packaging that the BT-12s ship in is impressive. I've saved it and use it inside of a hard-shell case for storage/transport.
The BT-12s work really well with our DSR112 speakers (small gigs) and exceptionally well with our JTR Noesis 3TX (larger gigs). I would change nothing about them - they are mechanical perfection. The 3TX are tall, but with the BT-12 they remain perfectly stable and balanced, no matter the height or angle. It's really impressive.
It was also very surprising to witness how much they help with directing sound to where you want it to land... changing the tilt angle from 3-degrees to 6-degrees makes a very noticeable difference in most indoor environments.
I was hesitant to spend the $$ on tilters, but after buying (and promptly returning) the K&M "tilters" I decided to invest in the BT-12, and have zero regrets. I only wish I would've bought them earlier!