Some traces show individual interface names, some just show device names. Any particular reason to go one way or the other for PTR records (doing a single device name for every interface seems easier and less-likely to screw up to me)?
Providing information where the packet went is much more precise if you provide interface indentification with the PTR. Putting speeds on the PTR´s is more a marketing thing since users are usually happier with empty OC3 than full OC12.
What about A records? A matching one per PTR, or just one A per device? Or no A records in the public DNS? Would round-robin A records (an A record for every interface address, all using the same device name) break anything (like performance measurement tools or network management tools)?
The "main" device name should point to an loopback interface to allow reachability when some interfaces are down. Some network management tools break with large aliasing but those should not be used anyway. Pete