I have tried three multi material (stud, metal and electric wiring) detectors. Each a bit more expensive than the previous one.

The latest one is the Zircon Pro SL, http://www.sealhardware.com/detail.asp?sku=4628012

None has proven very reliable.

Would anybody know if this Bosch one is good?

http://www.screwfix.com/app/sfd/cat/...49160&ts=13968