What Class A is better? SUGDEN FPA-4 or PASS LABS XA-25

I`d like experiences of the gurus.

Too many ignoramuses on this thread. If you don't know who Sugden is then why bother commenting? 
I'm using a Sugden A25B on my Altec 620 and it's quite a good little amp. Musical and warm sounding but not the final word in definition and clarity... I didn't listen to the Sugden you mentionned but it's most certainly good... I've heard other Sugden products and they all sounded good... Is it as good as the Pass Lab ? I can't tell since I never had the chance to listen to one... Sugden products are not known in the US but many audiophiles are using it in Canada...
As a former speaker manufacturer, I have listened to many, many amps and I have always liked the Sudgen sound.  Clean, pure, sweet, natural. For that matter, I like Class A amps. The FPA4, discontinued in 2019, was based on the A21, so you have some very good DNA there. But is is not the same as the A21SE. The XA25 is unlike other Pass amps, so you need to hear it to appreciate what it is. It has its own sound and is close to a single ended tube sound. It is actually the one Pass amp that I like the best. Read Teajays's and the others review. I have 4 favorite ss amps and the XA25 is one, which I also own. It comes down to your ears and what is in the rest of your system. But there is something special and just right about the XA25. I hope you can find some way to compare them side by side.

Before I went toward tubes, I looked hard at both but didn't audition. So I cannot give you the experience answer you're looking for. However, one audio dealer which a lot of people respect is Gig Harbor audio and they're very nice people who carry Sugden. If you called or wrote them to ask why they deal in Sugden, they might add some data to your inquiry. Yes, they're a dealer so they'll be biased toward what they carry, but sometimes these conversations yield nuggets. https://www.gigharboraudio.com/
I have the Sugden A21se and I love this amplifier, so much grunt it defies the power expectations of most, I’m using it with KEF R3’s and it’s a very nice pairing, the Sugden is just very musical and clean.