IMHO none of the anti solo mining myths are correct except one: pooled mining generates a steadier flow of income (at a price).

Myth 1: Mining in a modern pool produces less stale shares due to long polling, which the regular Bitcoin client doesn't provide for solo miners.

Fact: You don't need long polling for solo mining at all. Just set the askrate to something as 1 second. For solo setups the added overhead is below noise. You loose 0.5 seconds worth of work on average per freshly found block, but even the best pools with LP support cannot beat that in practice, since you seldomly get less than 0.5-1% stale shares (often more). This nonsense is even part of the wiki! There is no 1-2% benefit due to LP, in fact local fast polling is more reliable. Can anyone remove it?

Myth 2: Because difficulty constantly increases, joining a pool improves your chance to get any payback before the next difficulty increase, thus pooled mining has a higher profitability.

Fact: The premise is true, but not the conclusion. Solo mining has a low probability to get a large payout before the next difficulty increase. Pooled mining has a large probability to get a low payout before the next difficulty increase. It sums up to zero. Pooled mining does not increase your chances in a scenario of steeply increasing difficulty.

I think all other myths are self-explanatory nonsense.

There is not one benefit of pooled mining except less variance. You pay for this comfort with pool fees, missed transaction fees, stale shares, generally higher network downtime exposure, the risk of getting ripped off by a pool operator, implicit costs of sophisticated pool hopping (if you aren't the hopper). These costs are real, the costs of solo mining are purely psychological (not for the faint of heart).