Recent PHL-IAH flight (UA 420 on an A320), we were told on departure from Philly that we could use our personal electronics devices. Glad that UA quickly adopted the new FAA guidelines.
On approach to IAH, however, due to low ceilings and visibility, the Captain asked that all electronics be turned off due to "possible navigation equipment interference".
I have no problem complying with crew member instructions, particularly when it's the Captain. But if navigation equipment interference is an ongoing concern, why did the FAA lift the restrictions in the first place??
My approach into IAH on Saturday morning was pretty bad too -- I heard the pilot say in the terminal that he didn't see the runway until 200ft (which is decision height, so it's a good thing he did see it or we would have circled for a while!).
In my case, we had no such request. Like you, I wouldn't argue with it, but I am skeptical of the concern. This was an important component of the FAA testing phase to approve electronics during all phases of flight. If there was ANY evidence to suggest instrumentation interference, the policy would not have been put into place. Since the FAA offered no stipulation as to the usage of the new policy, I tend to believe the captain on your flight was being overly-cautious or is perhaps unconvinced that this new-fangled technology won't throw off his ILS.
As time goes on, I expect that this kind of request will disappear. It's still a new policy with its fair share of opponents.