I haven't stayed at one either (yet)*, but they are an extended stay type of property, and I have stayed at several other extended stay chains (tho not including PC's other one, Staybridge Suites), such as Studio Plus/Extended Stay/Crossroads and one or two of the smaller chains (whose names I can't remember offhand). In case you haven't used extended stay hotels before:

They're geared toward the needs of people staying for many days up to many months, but in many (tho not all) cases you can book one night stays if you want. So for example you get a "full" kitchen usually with some dishes/utensils rather than getting a restaurant or breakfast. At some of them (tho I dunno about Candlewood) the front desk is not open all night and (unless requested) linen service is only a couple times a week (for those staying that long). Amenities tend to be oriented toward what makes sense if you have to live there in a "home away from home" for a while rather than what you would need if popping into town for a night and jetting away early the next morning.

If you have stayed at Staybridge Suites, be aware that Candlewood is positioned as a value extended stay property while Staybridge is positioned as a more upscale extended stay property.

*Ok, now that I've explained all that, I can relate in context the one time I TRIED to stay at a Candlewood Suites a couple years ago, in Clearwater FL, where I was booking through a third-party website which kept throwing errors, and it turned out that the website I was using let me book any number of days but at least at that time that property wasn't allowing you to book stays of less than 3 days. (These days if we want PC points/miles we HAVE to book at an official PC website, so there shouldn't be any such confusion in the future for us...)