Stabilisers (including servo) are like a call girl. From Rs 1000/- to few lacs that is the range.
Pls remember :
for home theater use with average load, you need a 2kv to 3kv good factory made Servo Stabiliser and it costs above 20k-25k.
So hoping a cheap 5k stabiliser will give all mighty protection to your 1Lac+ system is a foolish dream.
Theorotically speaking, UPS that too ONLINE UPS in same load range is a better solution but that it requires a battery backup. Remember banks and even hitech gyms use a online UPS to protect their systems.
But for our Home theaters , a good Company Servo-stab would do, not one picked up from street-side electricity shop or even a mall.
V-guard is not a servo stab but just a stab.
Now the question of Inverters. Lots of companies sell their inverters with fancy names like Sine-wave UPS, offline UPS etc... these are good for power backup of your apartment but not for your home theater.
In fact , many amplifier compaines write in their manual, not to run the amp on a inverter backup.
Or a simple rule would be : the cost of power protection for your equipment should be from 10-20 % of the total equipment cost for the solution to be effecive.
So now a 1k Vguard should be good enough for a equip upto 10k ... how will it protect a 50 inch plasma.
SO choose your power protection wisely and carefully.
thanks