P&W’s first batch of dual-power units were successful, but not crew favorites because they didn’t like the rearwards visibility on cowled units. So the next batch (with a single Cummins QSK95 rated at 4200 HP) came with a traditional diesel narrow hood and the pantograph recessed in a notch in the carbody to keep within Amtrak’s D-05-1355 clearance plates

Subsequent orders – e.g. this D&H unit – were delivered without a recessed pantograph.

They are all in service.