There are 2 manufacturers of new R2R tape - ATR and RMG/Pyral (now known as Recording the Masters RTM). A new US tape made by Capture has been mooted as well.
Essentially, the ATR tapes are similar to the old Ampex and Quantegy, whilst the RTM are the old Agfa PEM468, BASF SM911 and SM900 tape formulations (with long play variants LPR35 and LPR90 respectively for the SM911 and 900). I use the RTM tapes all the time (LPR35, SM911 and SM900); I have not had any SSS problems and the quality has been excellent.
If you are in the US, you may find that ATR is cheaper. However, I have heard reports of occasional SSS, although I have not experienced this myself.
Essentially, the ATR tapes are similar to the old Ampex and Quantegy, whilst the RTM are the old Agfa PEM468, BASF SM911 and SM900 tape formulations (with long play variants LPR35 and LPR90 respectively for the SM911 and 900). I use the RTM tapes all the time (LPR35, SM911 and SM900); I have not had any SSS problems and the quality has been excellent.
If you are in the US, you may find that ATR is cheaper. However, I have heard reports of occasional SSS, although I have not experienced this myself.