I dont have any hands on with the 550. Although I looked at one in a 223 or 22-250 I think....maybe 223wssm.......long time ago, cant remember for sure. Anyway it had the set trigger etc. The kicker tho was CZ didnt have a chrome molly lined bbl/chamber. I dont know how to phrase it, but it was the same issue as the early M-16 in the Viet Nam era (minus the ball powder issue). Barrel life was less than half on a CZ vs what it was on a Win, or a Browning in the barrel burner calibers.
I dont know if they ever fixed the issue.
I will say this for C-Z though. They have a great warranty Dept. I own a C-Z 712 auto loader 12ga shotgun. Shoots great, feels great, but I usualy break it once a year for the last 4-5 years. Other than Duck season 2008 when nobody could get parts, the warranty Dept has been spot on and very timely in mailing me replacement parts.
I didnt think I was gonna get another C-Z, but I wound up with a C-Z Canvasback O/U 12 ga. 100% awesome shotgun. and not only does it look good, feel good, and shoot good, it hasnt broke yet, and I like that alot better than the warranty dept.
I have mixed thoughts on C-Z. I like the way they look, feel, and shoot, but the barrel issue on the rifle, and the reliability issue with my 712 dont sit well with me. However the Canvasback has impressed the snot out of me.