I think TIP and RING still has it's place.

Because of that...

I like using the PAP2 ATA to marry TIP and RING with VOIP. The support the PAP2 has for analog telephones far exceeds that of most of the TDM stuff I've seen.

FSK message waiting? The PAP2 does that.
Caller-ID? The PAP2 does that.
CPC that works right? The PAP2 does that.
48V talk battery? The PAP2 does that.
Call-waiting Caller-ID? The PAP2 does that.

(These all tend to be "problem areas" for TDM systems, don't they?)

You can even use a PAP2 to add MOH input or paging outputs to a VOIP system.