What is the best floor pump for road bikes??

Take it back to your local Specialized dealer, they might actually replace it on warranty. I cannot remember what the warranty is on S-pumps, but it is worth a try.

Blackburn pumps have a very solid lifetime warranty, but they never seem to have a well-built head attachment. My last Blackburn TP-4 had its head cut off and I installed a Silca presta-only, then it eventually died when we had a flood in our house. Currently my everyday pump is a Specialized Airtool Pro, and I like it as it is very stable with a large handle, has good air output per stroke, and has a solid pump head. The only drawback to it is that the gauge reads low by ~15 PSI. Once calibrated against an accurate gauge this is not a big deal and many pumps tend to exhibit this problem.

I also have a bottom-of-the-line Blackburn TP-1 from a few years ago. It has a steel barrel, a smallish handle and an cheapo plastic lever-type head. I keep it in my car for travel to races because it is smaller than the Specialized. It does not get used too much but does the job when required.