Nah, I do my business with people who I feel deserve it. I realize they have a huge fanbase here, I just don't fall into that group, that's all. As I said, I won't try to persuade anyone not to buy from them, but you most certainly won't persuade me either. /off topic.
There's a mis-conception regarding line-outs that is from old thinking. Line out just mean the amp stage is bypass for the "purest" sound straight from the the DAC stage at a fixed voltage level. This may be useful in the past because not all amps are equal, and that component and all-in-one devices may have a bad/poorly made amp that will affect the sound in negative ways, that is why there is traditional thinking that "double amping" is a bad thing, as you may be amping a sub-par output from the source. However now you are talking about extremely high end devices here such as the DMP-Z1 where lots of care is also put into the amp stage such that there's very little distortion and noise at the output, so there's absolutely nothing wrong with using the heaphone out to feed it into another amp.
Old wisedom usually have certain aspect that is based on truth, you just need to understand what it is instead of taking things on it on face value. Also as long as you keep an open mind and keep learning, your mind will never get old, and that's the important thing. You don't have to rush it, just take things at your own pace.
I'm sure the old wisedom that "double amping" being bad applies with older and lesser equipment, but modern equipment - even mid-fi ones - have specification that simply blows old equipment out of the water when it comes to things like noise and distortion that you don't have to worry about such thing as much as they used to a few decades ago.