There are so many threads on this; can't tell if this is the right place to put this but here is some feedback:
Used the Witch to add class levels to Undrella the Harpy in Legacy of Fire (I did this because we have a party of 6 and I'm finding that the PFRG characters are stronger than the old 3.5 characters so all CR's must be upgraded...). I gave her the Sleep, Charm and Ward hexes as a level 4 Witch on top of her base monster statistics (I wanted a fight against her to be a tough experience for the party if they took that route and this added flavor to the encounter). I am using a homemade version of the Harrow deck fate card system that was introduced in the CoCT campaign so one of my characters who had the Rabbit Prince card was "fate chosen" to be Undrella's favorite and she added her Ward Hex to him.
The Ward Hex is really good. However, I noticed issue with the other two. I think that the Charm Hex needs to be upgraded to minutes instead of rounds and the way it is written it seems to be too much weaker than a Charm spell. (example: if the one person that is affected is unfriendly and raised to indifferent, but still surrounded by friends that are unfriendly, it seems this is worthless because they will join their friends). I wanted to cast the charm spell but then the rest of the party would notice this and I figured a very unfavorable response would come from it because they were waffling between work with her vs. combat her. My intent was for Undrella to charm her favorite using the hex (while pawing over her favorite "rabbit price" PC) which I read as more subtle and definately more "new" than a spell but the duration was too short and weak for it to accomplish anything. As is she really didn't end up using any of her abilities to push them into the direction of helping her, I did that by roleplaying only and they were swayed by metagame information when they realized she had placed the ward on him. I only used her harpy song to bring them close enough to use her abilities...
Also, the sleep hex is a very flavorful item for the witch (like something from Mother Goose). It needs to also be upgraded to ten minutes per level IMO. This would be perhaps the witch's best offensive hex option but again it is sort of short lived as written.
There seems to be a void in the hexes and the spell list at low level (againt his was just level 4 witch) as there is really no option that can affect everyone in a group, so particularly if trying to work for a PC, this is a handicap that should be addressed IMO.
Overall, I think this really worked well as an NPC class and particularly in this encounter. However, I am seeing a real void in offensive versatility for the witch as a PC so I feel it would be quite weak compared to an equivalent Wizard or Cleric. I know that the hexes are the witches toys vs. feats but I think it wouldn't hurt to throw in some bonus feats to the build or perhaps a feat that can be taken to allow earlier access to the higher tier hexes or to improve the power of specific hexes. Another boon to this class would be to make some of the spells that are really in line with the flavor of the class to be accessed as lower level spells than a Sor/Wiz/bard would receive them.
I did also come across some questions that I think need to be clarified in the final text.
A.) I've posted this elsewhere but there is no information for starting gold for any of the six new classes. This needs to be addressed for someone to make a new witch by the book...
B.) As I read it, the Hexes are an "at will" special ability. However, there does not appear to be any text that specifically says this or tells how many uses the witch receives. The hexes are weak enough that they do not seem to be unbalancing as an "at will" the way they are printed but maybe if you make them stronger as suggested above you might want to limit them to witch level + int bonus times per day. It also would help to clarify what "type" of ability this is specifically (like supernatural, magical, etc.) to help tie this to the various spells that could be used to counter the hexes.
C.) The familiar specific spells really should have spell levels clarified with them. I was assuming that they are the same level as for a Wizard or cleric (shield of faith from her Owl familiar) but at higher levels this assumption might not be correct and sometimes spell level is variable by class.
D.) Just an added opinion - in line with the "mother goose" flavor - the witch [i[needs[/i] access to more polymorphing abilities earlier IMO.