Going inside the machine isn't necessary to minimise smells if a product hasn't been abused.
Pet and tobacco odors get past any filter to stink up the insides of a vacuum.
I wouldn't go as far as saying "mains-equivalent." Running a highly unscientific test, I ran the V15 2 full cycles, then the new "mains" (Sebo D4) uncovered quite a bit of stuff the V15 left behind
That is the trick every vacuum sales person uses to "prove" your existing vacuum is no where near as good as the vacuum being sold. Doesn't matter what vacuum you have, the vacuum that goes first always looses. Every time. Oldest con in the vacuum industry. Next time the Kirby or Rainbow or ??? sales person comes to your home, have them vacuum your rug with their demo machine, put a fresh bag in your existing vacuum or a nice shiny clean dust bin if it's bagless and show the sales person how much their expensive new vacuum missed. The new vacuum will lose to your machine. The machine that goes first always does.