Its definitely not ok. Its definitely not among the top 5.
I would rather go for Avira AntiVir Classic which is free. It has a much much better detection rate. If you want free you can also go for AOL Active Virus Shield. Or, go for Kaspersky if you can afford it. AOL AVS doesnt have web traffic scanning, but uses Kaspersky engine, so has a good detection rate.
Also, dont get blown away by AVG and Avast fans. Check out the tests (at Av Comparitives and also Virus.gr). AntiVir outperforms both of those.
Nod32 has a weak database and its detection rate is lower than Kaspersky and Antivir.