DNS cache questions

Question about DNS caching...

1. What is the DNS cache size measured in? Bytes? Kilobytes?
2. Is more DNS cache better? Would setting it to 10000 be better than 1000?

ubnt@erl:~$ show dns forwarding statistics
----------------
Cache statistics
----------------
Cache size: 1000
Queries forwarded: 29500
Queries answered locally: 9166
Total DNS entries inserted into cache: 49943
DNS entries removed from cache before expiry: 0

---------------------
Nameserver statistics
---------------------
Server: 50.116.40.226
Queries sent: 29500
Queries retried or failed: 0

Server: 107.170.95.180
Queries sent: 29500
Queries retried or failed: 41

Info about my setup is below...

ubnt@erl# show system name-server
name-server 127.0.0.1
[edit]
ubnt@erl# show service dns forwarding
cache-size 1000
listen-on eth1
listen-on vtun0
name-server 50.116.40.226
name-server 107.170.95.180
options domain-needed
options bogus-priv
options all-servers

Thanks!