They are good for what they are, which is TMCC electronics in a classic Postwar style engine. (though it will of course run in conventional as well, if you don't have TMCC or Legacy)
So they are not whiz bang details up the wazoo scale pieces, as you obviously know since you know it's based on a PW engine.
At the time CCI came out, while there certainly were scale pieces being offered, it was no where near the bulk quantities of different items being offered each year across multiple catalogs like we have now. (well, some scale pieces were offered long before that, probably late 80's onward, but it blew up a lot to rise to the amount of product we see now probably between 2000 and 2010)
If you look over catalogs from around when CCI came out(1997-2000 for all 5 engines, IIRC), there was far less product. A lot of people were still thinking (incorrectly, it turned out) of these being true collectables and possibly worth a fair amount of money in the future if they stashed them away. As a result, many are available, a lot un-run. People who truly bought them for what they are and like that level of detail, probably will still speak well of them. But anyone who bought them all on speculation of future value are letting them go for a lot less than they sold for (or they are coming out if estate sales, etc).
So electronics wise, they will never creep around a layout the way a Legacy or DCS engine will with many more speed steps, but they are a decent improvement to a PW classic. There are a few markings that identify it as CCI (gold bell/whislte, and it also says Century in small gold letters on the rear of the tender). If those will bug you, then that's maybe a negative.
Unless there turns out to be something wrong with the one you bought, If you go in with the knowledge of what it is and what it is not, I believe you will be happy when you get yours and play with it a bit. (of course at this point it's very close to 20 years old, so a thorough lube and oil is a necessity before regular running)