I have been playing the ressers for almost a year and a half now. I in no way think that they are UP even when I take out Kiri. We as ressers may not have the hard hitting, fast, amazing models that the Neverborn have but when our stuff dies we bring it back. Other factions cannot do this with the ease ressers can.
I found that there is a steep learning curve to the ressers that is not there with a lot of other factions. With the ressers positioning is much much much more important than the other factions. I find that I have to plan two turns ahead for where I want my models to be for what I have brought them to do. Compared to other factions where their main goal is to get in rage of you as fast as possible and blow you apart.
Also I feel that the complaints that our tools are old and out dated with crappy synergy is complete rubish. Our tools are just as good as every other faction if used in the right situations. I agree in a vacuum out tools are very underwhelming but when considering the strats, schemes, terrain, and what your opponent is playing it is very very easy for ressers to win.