The Good: Geometry is great. Downhills are superb. Climbs are ok,
The Bad: Weight. Some weak / underdimensioned components. Sizing is a bit far out.
I bought the Process 153 in mid jun. The bike has an instant feel of going fast downhill. The slighly bigger wheels does the job well and maintan momentum on flatter parts. Suspension works very well: the pike is almost as sensitive as my old Marzcocci 66. Rear suspension is great. Climbing is ok. I have taken the bike to some epic mountain 5-6 ours climbs and yes its ok for that - but it shines on the downhills. I have also done some enduro racing on the bike and its an awesome descender. The climbs did not kill me eihter.
Compared to Trek Slash (mid model 2014) I think the slash has better wheels but the fork is far more better on the Kona. Still think the Slash did handle well. A bit more playful at 17.5 inch (my kona is a medium bike).
Given the DH capacity of the bike there are some parts that simply does not keep up with the rest of the bike: breaks are far too week (shimano deore). 2 pistons are to small for this kind of bike even if there are a propper 203 mm up front. Uppgrading this winter.
Tyres are also a bit slippery. Rolls well but the front tyre (mine came with a 60 A high roller up front and a 3 c high roller back) are far to slippery in the wet. I would say the same for rear tyre. High speed flat landings on loose surface (we have a lot of them) feels a lot better after upgrading to Magic Mary (vertstar compond) front and Hans Dampf (trailstar) back.
I have also switched crank arms since both as been bent after rellatively small hits. The wheels holds up well.
On real natural trails this bike is at home like a fish in water. Small to medium drops, rock gardens, off camber drifts and so on is just what the kona whants for breakfast, lunch and dinner.
Size (me 5.10 and 32-33 inseam) and bike is size medium and feels a bit big compared to other medium bikes in my garage: scott scale and nukeproof scalp. Can´t see how this would be a bike for people being 157 cm ( I am 178 cm), Kona gives it a range from 157 cm to 183 cm tall for medium......
Overall: great geometry for me. Think again if your are like 2 inch shorter and aim of a medium.