The confusion about the metatype cost comes from the fact that in the original version, you didn't pay for your metatype, but you could add double your metatype cost to the 375 karma you could spend on Attributes. In other words, a troll could spend 375 plus (40 x 2), or 455 karma on Attributes. Metatypes are allowed to spend more because without flat costs, their Attributes are more expensive to raise. A human raising Strength from 1 to 2 pays 10 karma, while a troll raising his Strength from 5 to 6 pays 30 karma.
The errata (which I have heard is in the latest printing, but not online yet), has you pay your metatype cost in Karma (so a troll would pay 40 karma), and changes Attributes to the x 5 multiplier. I assume you would use the lower SR4A costs for bonding weapon foci, too.
It is important to note that all Attributes, including the special ones, are purchased in Step 3, so the limit on how much you can spend includes special Attributes. I originally assumed it worked like build points, where the limit was only for the core Attributes. A lot of people seem to disagree with this, and house rule it to be like build points (I don't house rule that much, but I would lean towards this house rule myself, since this limit seems to screw over awakened humans the most).
Beansidhe, you are not imagining things - the original karmagen system usually resulted in characters far, far more powerful than 400 build point characters. Even with the errata, they still tend to come out a bit better. The ironic thing is that I actually tended to min-max less with karmagen - with such a lavish allocation of points, I could create quirkier characters that would not have been practical to make with build points.
