Headphone Amp for Focal Utopias?

I am thinking of getting a preamp with a good headphone amp even though I do not have any headphones yet. I am thinking of getting headphones to listen late at night when the kid is sleeping.

Does anyone have any feedback on the synergy between the Focal Utopia or Focal Stella and the Benchmark HPA4 2 channel preamp + headphone amp?

I was planning on getting the Benchmark LA4 preamp (without headphone amp) but recently I have started to realize that a headphone could be more enjoyable late at night than the very low volume I currently use on my 2 channel speakers.

I am looking at the Benchmark preamps because I like the clear neutral sound signature.

Just bought a new Benchmark HPA4 preamp + headphone amp today. I am considering getting a used Focal Utopia to use with the HPA4. 

I don't want to explain why I am asking the following question. Can Focal headphone owners here chime in about the reliability of the headphones. Did you have to use the warranty service? 

I went to Amazon and read the reviews on the Focal Utopia and spoke to someone who has Focals. I will likely get the Meze Empyrean.

@yyzsantabarbara  Just curious, what made you prefer the Empyrean over Utopia? 

I have no clue about headphones. I am only buying them because I want something for late night listening while I work (after midnight). The dealer that I am buying the headphones from advised me to buy the Meze over the Focal due to quality control issues. He sells both lines and was not happy with Focal warranty issues. That is why I asked here but since no one replied I looked at Amazon reviews and those supported what the dealer told me. The Meze is actually $250 cheaper than the Focal with this dealer.

I should add that I know the sound of the Benchmark HPA4 since I have owned the AHB2 before and will be buying 2 more of them maybe this month. I wanted to buy the LA4 initially for my 2 channel office setup but decided to pay the extra $500 so I can waste more money buying high end headphones, which I know nothing about

Another thing in the favor of the Meze, paired with the neutral and transparent HPA4, is that the Meze is being described as a warmish sounding HP. Unlike the Focal which is described as being neutral and very detailed.