Jet2
They're getting them quick enough! I wonder if these are partly from other operators orders that have fallen through? I suspect they are getting them cheap but good for them if so. Obviously their business model does not allow for waiting for the 737MAX to come out as you eluded too.
I wonder how many of these will be used to replace older models and how many are going to increase capacity. They have 21 737 classic and 12 757 in their fleet that might be getting long in the tooth. It could be that the net gain in aircraft is negligible?