Help.... I'm scared to 'upgrade'!

It has advantages when you have to fit 4 RCA jacks, a ground lug, a PS input, and some switches for loading, along with a stereo balanced output, in very limited real estate.

Nope. The Zen does have a single output jack for balanced stereo. See the above posts ands see photos on the iFi website. It’s on the left at the rear. On the right you see the PS input. All specs say it is capable of a true balanced output.
Nice pun on SOTA. Those who don’t or won’t own a SOTA can also have atop drawer system. 

I'd never heard of that 2 in 1 type of connector for balanced output.  But then again, I have never owned headphones or any miniaturized audio components. So thanks for that.

Fremer's review stated: "The compact Zen offers a gain range of 36dB to 72dB with a claimed astonishingly low -151dBv noise floor, a useful switchable subsonic filter and a balanced output, something unheard of at this price point."

So yeah, THAT's a quiet unit. The first question though is how does it sound?  Also, I looked at a photo of the rear of the unit, and I see only ONE balanced output jack.  Do you need two Zens for balanced operation? (That would not be unprecedented; the Einstein phono stage offered that option for balanced mode.)  If the noise floor is -151dBv, I hardly think balanced mode would make an audible difference in terms of noise, because at that very very low level inevitably noise from something else in the system would dominate.

Now you guys mention it, and in the absence of rock solid evidence to the contrary, it may well be the case that the complaints about noise (hiss, as I recall, not hum) pertain to the JC3, and yes I do recall that the 3+ exists in part to reduce the noise. I am surprised that substituting a toroidal transformer helped to cure the problem, as toroidals do radiate.

For what it’s worth, I think I’ve read other comments to the effect that the JC3+ can be a tad hissy, john curl design credentials  notwithstanding. This is not an issue inherent to vinyl reproduction.

If sgreg thinks I am pressing for the OP to spend big bucks, that is not at all the case. The OP himself talked about a $70K Swiss unit and then about a 13.5K Accuphase. IMO you can acquire superb phono stages for much less. But on the other hand, let’s not pretend that the Zen is under-appreciated gold just BECAUSE it is cheap. The iPhono3 with an upgraded PS should kick its butt for way under $2K, and if it doesn’t I’d take a look at the linestage performance. 

IMO, you haven’t tried a really great phono stage yet, so it’s premature to conclude that the iFi Zen is some sort of giant killer. Most testimonials from other users would suggest that it’s not. It seems to be a good to very good phono stage “for the money “ and not more than that. If you own and only plan to own low output MC cartridges with very low internal resistance (e.g., less than 10 ohms), you might really like the BMC mentioned above or some other current driven phono of high quality. There are several other choices of phono stage that should outperform anything you’ve heard in your system. The other question that arises is whether the linestage section of your Accuphase E470 is limiting your capacity to get the most out of any phono stage. Something to think about.