marantz sa15s2 or sa11s1? which one to buy?

in the used equipment market the marantz sa15s2 and sa11s1 can be bought for roughly the same price (sa11s1 2,5 year old, sa15s2 2-3 month), however new prices (i know that sa11s1 is discontinued) are far away (sa11s1 ~3000eur, sa15s2 ~1800eur). which one should i buy? i have quad909+quadqc24+dynaudioaudience72. any help, opinion or recomendation is well appreciated.
The SA-15S2 has a nice warm tone and is very full sounding. It also has an optical input so it can be used as a standalone DAC. It only has single ended outputs though.

The SA-11S2 is a little more transparent and detailed, does NOT have an optical input, and has balanced outputs.
thank you for the answer.a question: is the sq on rb and sacd of sa11s1 uperior over sa15s2?