I have bought an APC inverter in April, 2007 and really happy about the overall performance, of the product.
I really didn’t look at the various options just went and got one at a very reasonable rate (as I had a cousin working in APC at that time) it was configured and everything went well this December, 2006.
In December 2006, on a day we started getting beeps & various sounds often and called the customer service, in the mean while we disconnected the device, it took them about 3 days to arrive and they replaced the battery under warranty, since then I dont have any problem.
One good thing is that I have old friend, who stays near my house and is an expert in UPS with more than 10yrs exp. So when there is a repair or service I make sure my friend is there so that they cannot cheat me, this was I think I was lucky. Either way, APC UPS really helped me.
Overall its working well.