Headphone Amp for Focal Utopias?

I use Focal Elex with the Simaudio 430 HA and it sounds wonderful.  I've only listened to the Utopia briefly, and not with this amp.  Definitely take into consideration what type of sound signature you prefer and find something complementary.  I've actually heard the 430 HA described as being "soft", a description which I don't agree with.  We all hear things a little differently.  I find it to be very detailed and neutral and a good match with all the headphones I've used with it including LCD-4, HD800, and Sony MDR-Z1R.

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?