EDP in a low-level effects loop

[Mark Hamburg <mark_hamburg@baymoon.com>]

I'm looking at picking up a Tech21NYC Trademark 10 as a VERY portable amp.
The one complaint I've seen in reviews is that its effects loop has trouble
being used with some effects because of the level at which it operates. 
Here
are the specs:

    Effect Loop Input Impedance: 1M W
    Effect Loop Input Level:  approx. -20dBm
    Effect Loop Output Impedance: 1K W
    Effect Loop Output Level:  approx. -20dBm

Will the EDP have any problems with this?

Thanks.
Mark