I just bought one a couple weeks back. I like it just fine.
Supposidly these are made from Colt M16A2 rifles surplused out of some South American country's arsenal.
Not a bunch of factual info floating around the net about these rifles.
My Century C15 has new lower receiver(forged), new stock/handguard/grip, new springs, maybe a new barrel(fat barrel, no marks, not in the usual A2 configuration), probably a new trigger assembly.
Looks like most of the rest is used Colt parts. Some of the used parts are not refinished, but most of the used parts are. The rifle appears just not quite new! More like a refurbed and refinished milsurp than a brandnew rifle.
The only used/worn part on my gun that bugs me is the front sling swivel. The swivel is refinished along with the sight base and barrel, however it is well worn. Other parts show wear too, but nothing to cry about.
I love mine. Works just fine, eats cheap ammo, accurate, looks great.
If you think of it as a brandnew rifle, you may be dissappointed. If you consider it a refurbed military rifle, you will probably like it.
I looked at two of these my dealer had in stock, and chose the one with the tightest receiver fit. Neither one was just horribly floppy, but I've heard some were fairly loose fitting. The "Accu-Wedge" mine came with does a fair job of tighting things up.
I consider mine a refurbed rifle that works as well as a new rifle.