From what I've seen of EVE + isboxer it's whatever works for you. In missions I liked having just my dps targets + guns + overview of my dps alt available on my main screen so I had the highest dps uptime I could have. I was able to squeeze 4 toons onto one screen (drones/guns/ship stats/targets/overview for each), but you couldn't see anything else on the screen really which doesn't work well for pvp.