thinking should buy Panasonic invertor or continue use old 9 years old daikin?

Upgraded my master room Daikin non inverter R32 1hp to Mitsu JS series inverter 1hp JS10VF2



Take note that there's 2 version of JS series 1hp. JS10VF and JS10VF2. VF2 is slightly more expensive (around RM100 - 200 difference) but more efficient based on the spec. Worth the extra if you can get it

Planning to get two units of Daikin Revo cassette aircond 2hp for living and dining area in a double storey house. Two aircond shops I went to ask for price told me no point to get inverter since its open area ie expose to staircase n kitchen. Both shops said I won't get the energy savings effect from inverter. Just wanna ask if that made sense.