Haha, noooooooooooo.
It's good for netbooks because it's light (netbooks tend to have low ram/cpu)
But it's far from the best anti virus...
And the "doesn't slow down your PC" thing.... That only depends on the person's PC, now doesn't it?
Top 3 Big Anti Viruses are (In my opinion, and in no particular order)
BitDefender
ESET
Kaspersky
AVG is pretty good, but mostly praised as a free anti virus, as it's free version is quite good compared to others.
I'd also recommend always having MalwareBytes' Anti Malware, even if you have another antivirus, you should have it as well, it's updated daily and it gets a lot of shit others don't.