I recently changed the 42/34/24 crankset out on my Schwinn Sierra GS for one of the cheap Shimano 48/38/28 cranksets you can find on Amazon. Even though the new crankset is a cheap one with riveted rings, it works fine for my cheap bike. I did have to change out my bottom bracket from a 112mm to a 122mm, but I needed to do that anyway as my old one had a little play and noise. In my case, my original front derailleur was compatible with the new larger crankset, so I only had to make a minor adjustment to it. I am glad that I made the change on mine. Even though I usually cruise around on the 48t chainring, it is nice to have the smaller 38t one when tackling that big hill on my way home from work. It is at mile 24 of my 27 mile round trip commute, and by then my legs enjoy having the smaller ring on the hill.

For me, the biggest improvement in upping my crankset is that it gives me more favorable gear ranges for my two types of riding. I use the larger 48t ring when commuting. I use the smaller 38t ring when cruising with the family. My youngest daughter is tethered to my wife's Giant Sedona with one of those Trek tandem tagalong attachments, so we are quite limited in our speed. Before I changed out my crankset, I found myself wishing for a higher gear when commuting, and never finding that "just right" gear range when riding with the family.