I ran both... +4s and TR55's.

Ran +4s first...swapped them for TR55's after a forum said Bosch were junk. Got a less than smooth idle and some noticable, if by only a margin, flat spots at 4000 rpms + with the TRs. So I switched and never looked back on my 3rd set of +4s with 276K on the clock.

Never tried any other NGK product though...but in my opinion NGK are good products, just not in my car.