As long as replacement parts are out there, you will always see Knights well accepted in the muzzleloading market. Whether they are collector items, I kind of doubt it.
As big a shock as it was to see Knight go out of business, still it does not take away from their quality. Although there will be those that avoid Knights because of the customer service part. Its a mind set that you just can not get people to think differently.
For instance I was letting someone shoot my White one afternoon. While they bragged about how well it shot, their final comment was.. too bad there is no customer service. Which I replied if I ever need it, I will let you know.