Benchmar DAC-1 as pre vs Bottlehead Foreplay II

Hi all! Currently I am using my Benchmark as a preamplifier to feed two monoblocks Rotel RB-1091 and I like what I hear. My soucers are a Shanling SCD-T200 and a Primare CD21. However I wonder if I would get better results by adding a Bottlehead Foreplay II (with better caps and a stepped volume control) as a preamplifier. Any bottlehead and Benchmark users that can shed some light in this regard? Thanks in advance four your comments!