First (and I can't believe no one else mentioned this)
PLEASE buy yourself a couple of steel safety cables, and use them whenever you are clamping onto something. Not only will it save your gear if something lets go, it will save people below from potentially serious injury. Looking at your picture, there is a very small surface area of those SuperClamp jaws gripping the bar clamp. One decent knock, and the whole thing is coming down.
While I'm on safety, I would get extension cables for your mics so that your other gear can stay in a bag. Speaking of which,
I have used this bag for several years, and it has been great.
I say keep your 853s. I agree with opsopscopolis that going to state-of-the-art pro mics such as Schoeps are DPA is a case of diminishing returns for recording any sort of amplified show. I have used those mics before for what I do (choir, orchestra, other acoustic ensembles) and they absolutely make a difference when used in those situations, provided that the rest of your chain has sufficiently high resolution and low noise that those benefits can be realized. I am not criticizing anyone here who owns these mics or runs them with amplified concerts; if you can afford the very best, why not? I am just saying that for what you are recording, I doubt you could reliably pick the more expensive mics in a blind ABX test.
Side note: I am a huge proponent of the Line Audio mics pillowman recommends, but I would caution against using them if your mics will ever be within a few feet of a wall or a ceiling such as shown in your picture. They are subcardioid (halfway between cardioid and omni) and pick up quite strongly from the sides. I found this out the hard way recording vocal tracks in my basement with a CM3 boomed overhead. There were all kinds of early reflections from my untreated ceiling in the recording. These mics also need to be spaced wider than cardioids for proper imaging, so your rig will take up a wider space.
The upgrade I
would recommend is a new deck with XLR inputs and high-quality preamps (again, +1 to opsopscopilis). This will eliminate a box from your rig now, and allow you to use full-size mics down the road. The Tascam DR-100 mkIII is IMO the best 2-input deck out there. It is discontinued, but new units are still in stock at
Amazon and a few other places.