The DTs work like any other amp with stomp boxes in front of it.  I have a POD HD 500 and I am using a separate Tube Screamer and a 535Q Wah in front of one or both.  Since I always put those in every patch, I have them available all the time and free up the DSP in the POD for more delays and pitch shifting.

Here's my problem.....  the POD works as a midi controler but only for individual foot switches.  I have not been able to make the POD change amps on the DT when you change a preset on the POD.  So for example:  you would store a whole combiniation of fx and maybe use the POD HD in 4 cable mode with no amp selected so you want each preset on the POD to change the amp setting on the DT.  It doesn't work, however.  Or at least, I could not get it to work.  The L6 link makes midi changes on the DT but I can only assign individual switches on the POD to send midi messages or even multiple messages.

Anyone have a solution for this?