With a size 18 needle, my Brother XL 6452 sews through anything like buttah.

I also have a couple of older machines (both singers) that can do outside fabric+peltex+iron on midweight interfacing+inside fabric..and sew through all the layers for the stitching at the top. I always use 16 or 18 needles & this seems to work, and the presser feet have an 1/4" lift, so that probably helps, too.
PS. I have a Consew, too (I bought at an estate sale)..but, to be honest, I don't really use it that much, unless I'm working with leather or vinyl.