Back in 2014 I reluctantly bought fast track for Colossus because it was so busy and I'd hardly been on any rides - was at least a 45 min queue which was frustrating - but the main queue was well over 90 mins so in that respect it halved the queuing time.
As for security - understandable that they have it in place but it sure slows things down - would be great if they had more security points to speed up the process. Last Friday I went to CWOA in the morning and Thorpe in the afternoon - bag check at Chessie was pretty thorough but not so much at Thorpe. But at TP they have those scanner things you walk through but not at CWOA (that I noticed, or went through)