I just don't get this. I've seen people say this for awhile and i've installed kaspersky on a variety of machines (including VMs with 4 GB of ram & a single cpu) and its been quite light for me. Are you saying its heavy in terms of CPU usage or memory. I've seen neither. Granted i will agree its not as light as eset but 0 day protection on eset is bad and great on kaspersky though in most cases you won't need it because ESET's definitions are great. If your talking about memory utilization you should try bitdefender.........its night and day difference.
I'm just wondering if this harkens back to the days when kaspersky was heavy a long time ago. I sometimes see people say the same thing about norton/symantec. People norton is no longer heavy and it hasn't been for years and years and years. It might even be lighter than eset (if i remember last time i tried it).