FWIW, Florence's metrics are very similar to those of Carlos Rogers, and those of Fred Smoot circa Minnesota. He's going to allow 6-7 yards per pass in his direction. That's nickelback quality at best.
He's going to be 29 next year. He's better than, say, Kenny Wright or David Macklin or Mike Rumph, but he's not going to displace a healthy Rogers, an unhealthy Springs, or a prime-of-career Fred Smoot.
Basically, Drayton Florence does not lessen the need for Shawn Springs to play CB1 for us. However, he does address a select short term need for us until we can get Rogers back in the lineup. He's no Brian Kelly though