Choose Escher Wyss if it's CHF 100 cheaper per month, the commute to HB is 3 min shorter — more central and connected, there's a denser restaurant scene.
Choose Mühlebach if it's noticeably quieter (48 vs 54 dB), it scores higher on safety (8.5 vs 7.5/10), it has better green-space access (5 vs 4/10).