Sharp Inverter AC's are generally preferred due to good performance & lower power consumption but some exaggerated claims regarding power consumption has been made..
Well Sijith it all depends on your city[ after sales service is most important factor]
If you dont live in top tier cities....avoid japanese companies and go for korean ..
If you live in metro cities you can go for these..I am giving you approximate MRP..
Based of COP[ Coefficient of Power] both hitachi and sharp [ both in 4.0 league] are excellent...but hitachi costs 5 to 8 thousand more
Hitachi :
Kampa : 44000 INR
Ace : 45000 INR
iclean : 55000 INR
I don't think Hitachi is a desirable brand at all. Moreover Hitachi service is generally known to be lousy, and a fellow mod in Chennai has experienced the same.
It's a bit unfortunate since they're the only ones who seem to be rating their compressors as capable of operating under 52C ambient temps.
I'm not saying Sharp is any better, since their support is non-existent in Chennai, to the point that even their brand exclusive store actually switched over to Panasonic.
Sharp XP13's COP is about 3.63 not 4.0+. Oddly a Korean company has broken the 4.0 COP barrier for 1T ACs
Another interesting parameter is that compressors tend to get more efficient at lower loads. Sharp's compressors seem to scale pretty well at low loads, whereas Hitachi compressors barely budge by like 0.2 COP.