I have the Process 134 DL, so can provide some input. I think the weight is fairly close to the 153, so it's fairly similar. In my opinion it pedals efficiently - that's compared to riding my hardtail (Soul) which had been my only bike for 3 years. It climbs really well without needing to touch the rear shock lockout, and I'm not a great climber. It doesn't feel at all heavy to ride, just very confidence inspiring, balanced and responsive. It's a lot of fun, and feels like Kona have got it just right.
The only time I notice that it's a few pounds heavier than my hardtail is when I have to carry it upstairs to my flat. I was worried it was a bit heavier than average, and would be slow, but it really isn't heavy to ride, and it can shift - even with me riding it
In the past I've ignored a lot of bikes that are heavier, it's easy to think it can't have been well engineered if it's a little more than the norm, even if the weight difference is only marginal. I was lucky that a friend let me take his Process to Cannock for a test ride. I knew it was the right bike for me just minutes into the ride.
Whatever you choose, I hope you have fun with it!