Timber containing nails and screws, mixed stud and board, plastics, and light non-ferrous and thin ferrous section - the mixed and unknown content typical of demolition, strip-out and refurbishment. It is designed to survive hitting a fixing rather than to excel in any one material.

No, and that is the trade. Finish is rougher than a crosscut blade and cutting is slower than a rip blade, while costing more than either. What it buys is not having to change blades or stop when the material changes, which on unknown work is usually worth more than the performance given up.

Tougher, more impact-resistant carbide than a fine wood blade uses, combined with a tooth geometry closer to the negative-rake metal pattern so the tooth does not grab on a hard inclusion. A fine wood blade meeting a nail typically loses teeth immediately; this survives it, though not indefinitely.

On finished work where the cut face will be seen, and on production cutting of a known material. In both cases the dedicated blade is faster, gives a better result and costs less. The multi-material blade is for unknown content, not a general upgrade.

It is designed to work at normal circular saw speeds, which is part of its convenience, but cutting metal within a mixed section still benefits from a steady moderate feed rather than forcing. Pushing hard through a hard inclusion is what breaks teeth even on an impact-resistant grade.