I have been using the regular set of Rondo on my French cello for a couple of years and find them very stable, long lasting and of great quality. They solved my life long problem with the D string on this particular cello making the instrument very even and sonorous in all registers. Recently I started playing on my new cello which I commissioned from the brilliant violin maker Stefan Valcuha. It is a Montagnana model so it is a different animal from my Strad model cello. On this cello I had initially installed a regular set of Rondo but on the advice of Stefan I tried the Rondo Experiece A string which has less tension. It opened up the entire instrument more specifically the highs and low ends. It is a game changer for me. It adds brilliance with more flexibility. I highly recommend it.