I have been using the Voltas Split Ac 1.5 Ton Model for more than a year now.
It has not required any service till now and has performed brilliantly even on extensive usage. My AC runs for an average of 8+ hours per day and I always try to use the 24 degree Economy Mode as it saves power to a huge extent.
I have a considerably large room but still it manages to coolen it to a great level within 5-7 minutes of operation. I am extremely satisfied with this product.