Why does the 2nd level of PQ bonus require one extra ability point?

Yea. The quality is base*bonus, rounded down. That means the 10% bonus is significantly better than the 5% bonus.

The 5% bonus gives one extra planet quality for all planets ABOVE 15, compared to no bonus at all (and considering that 15 quality is the most common suitable planet, that's important).

10% bonus increases the quality of planets by 1 more for every level except 16 (base) compared to the 5% bonus increase - ie, compared to base, 10% bonus boosts you 2 levels except for 15 and 16, where it boosts only one level.

Calculations assume both Soil and Habitat, but not Terraforming.

I've got a chart showing the effects of this at http://geekzilla.org/galciv/pq.html if anyone wants to see it without doing the math

Quite frankly, I don't find that to be a particular convincing reason to waste an extra ability point on. It doesn't matter how the rounding is done unless there is an unusual abundance of planets just around the cut off value after all.

Uh... yah... how does that relate to the 10% bonus taking 7 picks again?

Maybe during playtesting they found that 10% is the "sweet spot" in terms of cost/benefit, and so made it cost more for game balance reasons?

10% is better than twice as effect as 5%, but not by much.

Honestly, I've found that I go +15% or nothing. I think this pick is the most powerful available, and may need rethinking. :-/

~SDC~

That's what I'm saying - it's the most powerful pick available.

~SDC~

Er, wait, I'm not. I'm saying that its more powerful than its cost. The planet quality bonus gives you a host of benefits that you couldn't match by spending the same points on economy, manufacture, tech, and the like.

~SDC~

On medium maps, at least, I find the +2 speed pick to be more powerful. At least, it is a heck of a lot easier to win games with the +2 speed pick.

+15% PQ is a very close second, tho.

The 15% pq is nice and I'd say it gets nicer each map size you move up. As far as it being overpowered, I think having to use 9 ability points seems reasonable. Although it would be nice to see the AI get that trait and colonize level 14 planets. As it is now 14 planets are just sitting their for colonization at my leisure.

~SDC~

I've seen the AI get the enhanced PQ ability (up to 8%), but they seem to be hard coded not to colonize anything under class 14. Technically speaking, even a class 12 would be of some use with the +15% PQ trait. Just a bit of propaganda would do wonders, and it's very helpful for extending your range to make leaps between star cluster.

My rule of thumb is that I want my planets to be at least class 18 after SE and HI, so I would only be able to go down to class 14, even with +15% PQ

I love the 10% PQ pick. I take that with minor research, morale, and diplomacy benefits every time. In an "Uncommon" or "Rare" good-world map, it gives you a great advantage; in a Common, it's still nice, but the extra points available for the other skills nicely complement it.

I would agree, though, that PQ is probably unbalanced compared to the other abilities. Very little in the game increases PQ w/o playing Precursor Lotto...