I bought one of these on Monday from a seller in Germany and it arrived today so I have been putting it through its paces. I have been curious about these tuners as my first 'proper' tuner for DXing was an ST-SA3ES and this tuner is its 'big brother', so to speak. Apparently it has had some adjustments to the distortion levels (THD I assume) and the signal strength readout - I was chatting to Andy about this in the Skywaves chat and he can probably explain this bit in more detail.
Anyway, it is very solidly built, weighing 6.3 kg (compared to the 4.5 kg for the SA3ES) and has the same set of features including full RDS (PS, PTY, CT, PI, Traffic, News, EON) and I must say it is good to have access to PI codes back again for the first time since late December 2006! A very useful feature, particularly during Sporadic E openings, of course. There are a couple of other minor features added on top of those of the SA3ES but not of relevance to DXing. The selectivity of this tuner is also a pleasant surprise, as it is definitely better than my old ST-SA3ES (a UK model) despite the selectivity specs for the SA3 and SA5 being the same. I wonder if the Euro models have slightly narrower filters installed than the UK ones (I'm not even sure if the SA5ES was available in the UK). Todd Emslie reports that the SA5 has 180 and 150 kHz filters installed and this sounds about right to me. I can tune 200 kHz either side of the Wrotham BBC nationals (about 27-28 dBf) without splatter, something that wasn't quite possible with my old SA3. Sensitivity as you would expect is excellent.
There is a slight quirk with this particular tuner (isn't there always?) in that there appears to be a small amount of 'MPX leakage' when mono is selected. So it doesn't quite shut down the stereo circuitry with the result that there is a low-level hiss on marginal signals and a vague sense of stereo separation. I seem to remember reading something about this on the Yahoo FM tuner forum regarding another Sony tuner but I can't remember where. It isn't a big problem though. I'd guess that something needs adjusting somewhere. Maybe it happened when the tuner was tweaked?
The sound quality is very good, but again, it seems to have a slightly rolled-off upper treble compared to the Denon TU-800L. It is more ruggedly built though and looks very attractive.
I was hoping to test it out during E-skip today so I could assess how quickly I could get PI codes and PS names from continuously varying signals but alas it was not to be as the Es cloud was just a little bit too far east for me to tap into. I hope there will be at least one more opportunity to test this before the end of the season.