We are debating between the Lennox XP16 4 ton heat pump vs the Trane XL16i heat pump. It will be a dual fuel system for both and they are around the same price. Are there any opinions on these brands or models? We like the Trane dealer, but feel that the size and efficiency of the Lennox might be better for the price. Is it usually recommended to get the extended warranty covering all parts and labor? Thank you.