pawsplay
Hero
Designing a good PF class is relatively more difficult than designing a base class for straight up 3.5. The first difficulty is that Hit Die and BAB are generally tied together; while logical, and rarely much of an issue in 3.5, these were areas where last ditch adjustments could be made, such as the ranger and scout's anomolously low and high HD, respectively. A second problem is that the goal of filling every level with an ability not only requires that classes be given plenty of stuff, but also restricts the kinds of ability that can be handed out on a repeating basis. In 3.5, if an ability was about twice as potent as sneak attack, for instance, you could have it advance half as quickly, but in PF, this would leave dead levels.
Taken together, it is very difficult to do an Unearthed Arcana cut-and-paste class design. For instance, transplanting fighter feats onto a rogue would require some fiddling with the progression, while an ability that advances every five levels cannot be swapped for one that advances every three. It is not sufficient for the total to be roughly equal, but the abilities must also be lain out level by level.
Taken together, it is very difficult to do an Unearthed Arcana cut-and-paste class design. For instance, transplanting fighter feats onto a rogue would require some fiddling with the progression, while an ability that advances every five levels cannot be swapped for one that advances every three. It is not sufficient for the total to be roughly equal, but the abilities must also be lain out level by level.