I have a first year (1961) .308 model. I like the gun and it came with some beautiful wood - once I got the old finish off that had been left by the previous owner.
Devil dog has got it right about keeping the gas sytem clean. The gun is very similiar in function to a M1A - it's just alot more trouble to get to the gas system on the 100.
Another thing to consider is that there are NO spare parts available for the 100 these days. Winchester sold them all off about 15 years ago and even those have been used up. This gun can be rough on the bolt carrier rails that attach to the gas system and again, there ARE no replacements - I had to get mine welded.
It's an ocassional plinker for me these days - I just don't want to beat it much so that it doesn't break something else.