Sony XA-5400es player...Giant Killer or just Ok?

Surely your dealer will let you audition the Sony. If not, take your business elsewhere. Just my opinion,nothing more.

I purchased a new 5400 not long after they were first released, the sound was fairly good for the price but not spectacular. Unfortunately mine broke several times, they replaced it with a new one that also broke within 6 months. I finally gave up and purchased something different.
I always chuckle when I hear the words, " giant Killer " thats a story book thing, it just doesn't happen in audio.

I see you own a 9000ES. If you have a lot of SACDs, the 5400 is very good with that format. If you're satisfied with the 9000, you'll be satisfied with the 5400. Other than that, you get what you pay for. It's a well-built, good-sounding machine.

And, with the wide range of comment on it here, on other forums and on other websites, the feelings of others are widely available. A handful of additional random opinions won't be definitive.

You will not know if it is the "real deal" until you listen for yourself.