To cluster or not?

I’m pretty new to couchbase, I have been using it as a memcached backend for the iis iteration of mod_pagespeed. i currently have a CE setup of 3 nodes in a cluster. Recently for some reason, some have auto-failed over. When it does that, it brings pagespeed to a crawl, and wrecks my page load times.

If the iispeed config has me list 3 servers, and is based on memcached, should i even bother clustering them, or just setup 3 or even 2 distinct nodes?