Hi Farhan,
Sorry for late reply.
My experience using LPG is very good. Previously I get it on Suzuki Khyber and now on Liana.
I have installed torodial cylinder (space where spare tyre are kept in trunk), so incase i need to keep big luggage / big, i can keep it.
This cylinder also has space of 35 litre.
Currently, per litre lpg give me 7 km to 8 km with AC. right now rate of lpg is 86.26 per litre. but it come down to 50 in summer season.