I've seen a couple posts about stratum proxies only being used for 1 to 2 cubes, but after monitoring my slush proxy while a single cube is running at 31Ghash/s... I'm seeing a very small load, thus one could reason that I should be able to run a lot more cubes through it. I just ordered a couple more, so when they get in... I'll update this with the proxies performance. Based on the numbers I'm seeing, there is no reason the proxies couldn't handle quite a few cubes.
* I am switching everything over from monitoring on SSH to SNMP; so please ignore the "?" on physical memory... the SSH Meminfo 3 shows that only 25% of 1GB is being utilized currently. Load average is < 1, CPU utilization is only 8% and network traffic is only 261kbits/sec (that is 0.03 MB).
http://s28.postimg.org/xcpema1ml/bcproxy1.pngShaker