It depends on what you expect to cut with the serrated part, and how the plain edge does compared to the serrated. This was recently discussed in another thread, but to summarize, a properly sharp plain edge can cut as well as a poorly designed serrated one. The hollow ground Bucks can actually create more friction cutting plain edge through cardboard because they wedge in the cut; Buck's serrations on the same blade are shallower and do well if not better.
Along with all that is the user's perception of ease of cutting. The same knife shows similar performance on rubber hose, but a real SnG outcuts it (to me) because it is flat ground and doesn't wedge in the cut as much.
Each type of blade with it's included serrations should be considered separately. The combinations of blade grinds and types of serrations create a lot of complex differences, so there is no pat answer which is best. Add to that the loss of an inch of working blade length for deep clean cuts; some users reported in the thread increased difficulty cutting meats as the serrations just clogged up.
The promised benefits of serrations are also suspect: the concept they are always sharp vs. sharpening them, the implication the plain edge isn't being kept sharp enough or abused, and the cool look vs. not really doing that much. Makers seem to support this last line - most serrated blades come in medium to low performance steels or heavily marketed brands to the masses.
Which brings us back to how much you cut stuff that needs serrations. For lots of long time users, not so much to find an overall advantage. We know how to cut.
I say no it can't. serrated edges are made for cutting heavy material much better than a plain edge. each blade design has a special purpose. a plain blade is good for all around cutting but not meant for any heavy saw type cutting.
For myself, I find a plain edge seems to work fine for the majority of cutting jobs I do, even including cutting most types of cardboard; some serrated blades seem to become stuck or not push down as easy in certain cardboards. I have found some advantages to serrations, however, particularly when I had to cut some marine rope; my very sharp plain edge would initially slide off. It could accomplish it, only the serrations did it much faster, easier and even cleaner.
I think it also depends on the serration pattern. I dislike serrations that are too thin and pointy, as they tend to hang up and not cut right for me. My favorites are the Spyderco or Benchmade-type patterns. I find the BM types generally cut a bit smooter without hanging up, as they're a bit rounder, but the Spyderco style cuts marine-type rope best.
That said, since I very rarely find cause to cut rope, I still prefer a plain edge overall.