Bob, my MM16 pretty much as a 1/2" 3 tpi blade on it full time at this point. I have other, narrower blades, but rarely use them for the things I personally tend to use the bandsaw for. If the smaller machine is staying in the shop, I'd personally put a 1/4" or 3/16" blade on it for general 'scrolling' and keep the larger machine setup for heavier work.
As to the carbide blade question...I had one years ago and it did indeed cut wonderfully. But it was darn expensive "tearful moment" when it suddenly got buggered and became unusable due to a stupid mistake I made during setup, leaving something loose that shouldn't have been loose. Re-sawing softwoods can easily be handled by a "regular" 3/4" or 1" blade and there will also be a thinner kerf. And these blades also work well for hardwoods, too. I'd only do the carbide again if I was getting into the situation that I was going to be doing a lot of re-sawing to justify the cost of the carbide tipped band, rather than general purpose work. But that's me...
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The most expensive tool is the one you buy "cheaply" and often...