Generally speaking an AVR is judged by it's build quality and then features. Usually the heavier AVRs are said to have a better power supply (be it EL core or torroidal type etc). Older AVRs have always had better transformers, better caps etc. Digital power supply? (Search me!)
An AVR which is 4.5kgs in weight ?!? Makes it very dubious to me at least. Check out the internal images of this AVR online. Make sure it has enough number of inputs and outputs to serve your needs. It is always better to buy a better and beefier AVR (budget permitting of course) as it is something people do not change overnight and trying to make it as future proof as possible is one of the general aims of buying an AVR.
Also US AVRs run on 110v, so you will have to factor a step down too. There are enough discussions about this in different threads.
Go through different threads, see if you can get a better deal here in India itself. Even though a bit costlier, it might give you more peace of mind.
Just my thinking that is all.
Vinod
PS: If this is what you are planning, this weights 9.1 kgs excluding the packaging:
Harman Kardon - Beautiful Sound