I agree that having pin one, and in this case every tenth pin, distinguished by pad shape aids in debugging. But as a circuit designer, I have to point out that you only debug the board once but manufacture it forever. Though I have to debug the board initially, manufacturing's long-term needs are more important than my short-term ones. As for field service technicians preferring this old method to make troubleshooting easier, I would point out that most companies no longer find it economical to have field service people debugging boards to the chip level. It costs way too much to train and equip field service people to this level of expertise and my experience is that they often wind up doing "shotgun" replacement of parts and poor quality rework. This makes the feedback to engineering as to failure mode quite useless. After a board has undergone such "field repair", it is often impossible to tell what, if anything, was ever wrong with the board. After seeing some of these beauties, I would never let them go anywhere but the trash bin!

IMHO, it is more economical to swap out bad boards and send them back to one place that is equipped to handle fault diagnosis. Besides, if you want to keep tabs on failure modes and track down root causes to improve your designs and processes, this is the only way I've seen that's effective. Once you do this, you often find out that many of the returned boards are not actually bad. The technician often does more than one thing on site and it turns out to be something else that was the failure: an unseated or intermittent connector termination, a software parameter, a different board if more than one was returned, etc.

With this in mind, my suggestions is to make all the pads on surface mount parts the same and denote pin one with a single silkscreen dot (outside the component body, please). I feel this meets everyone's requirements well enough: manufacturing can inspect for orientation and the back end repair folks have pin one marked. For through-hole parts where there is no back side silkscreen, use a square or rectangular pad on pin one that has the same length and width as the other pads.

When we designers and manufacturing engineers do our jobs right, there are very few boards returned for repair. When you consider the economics of PCB assembly manufacture, it makes great sense to design for manufacturing and to design for test, but very little sense to design for repair at the board level. There are some special exceptions to this where the board cost is extremely high and the total number manufactured is small, but by and large I believe this is the way to go.