I believe Brand C makes higher quality parts, and I have had very good luck with them. I have had numerous problems with Brand CT parts not wetting with solder during assembly, but I cannot say for sure that it was the parts at fault, or that they make substandard parts.
What can be said is that changing the vendor of any RF parts invites variations in performance. Making fixed tuned VCOs and other tuned circuits makes any RF engineer nervous, and when the vendor is added as an additional variable it can cause loss of sleep. These parts are specified value at some low frequency and as the actual frequency of operation moves up, circuit performance varies depending on exactly how the unit is made - wire size, winding pitch, bobbin dielectric constant, etc. So when a circuit is in tune with a Coilcraft part, it may, or may not work with someone else's part, and it's almost impossible to predict what will happen unless you actually try them (or do a lot of S-parameter analysis and circuit simulation - big $).
Will they work? Likely.
As well as Brand C? Probably.
For sure? No way I would say that!
I wouldn't switch unless it was a substantial cost savings and you are willing to spend some engineering time on any problems.