the problem with this is you have no idea if it is due to bad luck or a setup issue.
This.
Unless you are confident in your software setup, and have monitoring in place to ensure that everything is working correctly, and that you will know if it's not, the risk of mining for days/weeks/longer on a broken or underperforming setup outweighs any disadvantages you may encounter mining on a pool.
Exactly why I prefer to mine on a pool rather than solo, since a while now. I'd found lots of block in the pool, that would have rewarded me much more if I had found them solo mining, BUT, in solo mining I dont have a way to know the rigs are hashing fine, on the pool, I see if there is problem, reboot machines, fix setup issue..
It's clear that I would have found half of those block if I were solo mining..
At current difficulty, and the rise comming, I would'nt feel comfortable to solo mine under 10 Th/s, even at that level of hashing power, I would still use a pool.