It's a dilemma of memory vs computation. It depends on what we expect/prefer: FM that takes a lot of memory or FM that use computation resources when require

It's a dilemma of memory vs computation. It depends on what we expect/prefer: FM that takes a lot of memory or FM that use computation resources when required only. I tend to think that in general expectation from FM is to be very small in memory demands and take valuable computational resources only if it is absolutely necessary.