Here is my arrangement of the concerto for 2 violins-arranged for 2 electric guitars and srtings:

Movement 1:
http://www.youtube.com/watch?v=WA2H7Z58jGQ&list=UUv3ykLduG22Jl2YW5QOF7hw&index=15&feature=plcp

Movement 2: http://www.youtube.com/watch?v=vLjQejL98Qs&list=UUv3ykLduG22Jl2YW5QOF7hw&index=16&feature=plcp

Movement 3: http://www.youtube.com/watch?v=QRcD11ADcRY&feature=player_embedded

Those are interesting. I'm a purest though. So I might not be the best person to offer my opinion. I find the sweet sounds of classical music on the original instruments they were originally played on (I play the piano, myself) absolutely priceless. I do think you did a good job.

I preferred two and three over 1, but they were nice.

Not many people play the instruments that concerto was written for. The violin of Bach's time was not nearly as refined as our modern violins. Same for most instruments. Want to hear the same sort of violin Bach had in mind? It'll cost you $18,000. http://blogs.wttw.com/moreonthestory/2010/07/27/for-sale-18th-century-violin-asking-price-18-million/

If you hear horn music from any time before the mid-19th century played on a valved horn (one with keys), you're not getting the "original" sound. Before valves, horns were just tightly wrapped tubes of brass with a conical bore. Modern instruments aren't "better", they're just different.