It's not bad, as a full lookup puts it's toll on the root servers. It's common because in RFC1034, section 4.3.4 states that a server /can/ do it, not that it must or must not.
Uncached:
monk@deathstar:~$ time nslookup www.ais.net
Server: 127.0.1.1
Address: 127.0.1.1#53
Non-authoritative answer:
www.ais.net canonical name = ais.net.
Name: ais.net
Address: 207.251.194.49
real 0m0.562s
user 0m0.004s
sys 0m0.020s
----
Cached:
monk@deathstar:~$ time nslookup www.google.com
Server: 127.0.1.1
Address: 127.0.1.1#53
Non-authoritative answer:
Name: www.google.com
Address: 173.194.43.20
real 0m0.040s
user 0m0.000s
sys 0m0.008s
Look at the real time for both.