"resolving is slow" doesn't really apply to Namecoin - that complaint must refer to some other software interfacing Namecoin to DNS or a browser.
Normally, I use DNS for resolving (no browser mods required). Namecoin is a database. Your DNS backend can query your local Namecoin node and cache, or just batch convert all current names to a BIT zone periodically. I do the latter - although it means my snapshot doesn't include the very latest (has never affected me).
I have also heard of browser extensions that query a namecoin node directly. I do not like that approach at all. Just use a DNS proxy.