You absolutely need a convertible inverter AC with both vertical and horizontal vent adjustment. Since I switched to the Panasonic convertible one last year, my bill has come down a lot. Being able to run it at 40% with the vents directed towards me when I am alone in a room has cut down on the bill a lot.
Among the mainstream VFM options, Panasonic makes the most sense followed closely by LG. Daikin doesn't have a convertible model for mainstream prices whereas the Bluestar/Carrier models being sold here are costlier and more inefficient than Panasonic/LG. Mitsubishi is at the top-end but far too costlier for most budgets and you will not recover the price even over a decade.
Extended warranty for ACs is simply not needed. I asked the service person offering it as to what the main issue is, and he stated gas leakage which is not an issue at all since none of the ACs over the past decade suffer from leakages, saying it as someone who knows other Voltas ACs that have been running for 7 years now, and which costs about 500 bucks to refill. The compressor is the costliest to replace, but most offer 10-year warranty on that separately because it nearly never fails. The other part is the PCB which can be a coin toss like any electronic board but also unlikely considering it is in the indoor unit and not exposed to harsh conditions.
