Interesting query. I look forward to the responses as I have been thinking of one of these units myself.
I've had mine since early June. I don't remember it being as bass shy at first listen as you seem to be experiencing. It did smooth out some over the break-in period but I thought it sounded pretty darn good right out of the box.
Compared to other good units I have tried in the past year: Lexicon RT20, Bryston BCD-1, Meridian G08, Modwright Sony 9100ES, Musical Fidelity A5; As espected, the 5400 is great for SACD playback, but quite surprising on redbook cds. That's what sold me.
My experience was that the bass increased in suppleness and tunefulness over a period of a few hundred hours. It got slightly deeper, but not so much. The bass became more integrated into the music and developed more propulsion in songs where the bass really drives it along.
I noticed the bass right away. It was more prominent than my modified Sony SCD-XA777ES. Still, hang in there - break in does vary from unit to unit.
I too purchased one a few months back. I've owned a lot of players and I enjoy this one as much as any I have ever had.
(various Sony's including an SCD-1, Meridian 508-24 and G08,
Ayre, Cambridge 840c)I wanted a player for both formats and I have not been disappointed at all.
To your point, I have not found the player to be bass shy at all. Just the opposite. It has very deep and powerful bass when called for. It does this with extremely good definition and delivers what is on the disc. The player has excellent drive and a wonderful overall smoothness. I just can't complain honestly.
Like many others here, I have found the Sony 5400es to have appropriate levels of deep bass right out of the box. However, its bass definition is not as good as that of my Cary Xciter DAC (using the Sony as a transport via a 0.5 meter coax cable). I suppose my Sony is still in its break-in period (thanks, Metalla and Bigtee, for hope that the Sony's bass definition will improve). But it's an excellent RBCD and SACD player overall, and a bargain.
I also had an SCD-1. The 5400 outclasses it in every way except cosmetically. The SCD-1 is one of the finest looking pieces of audio jewelry I've yet to lay eyes on. Is anybody running XLR interconnects on their Sony 5400es? Was wondering if this player was a fully balanced unit. Don't see it advertised as such. I guess it would be a no brainer if it was. Just curious if anybody could give a little insight.