Well, I finally did it. I sold my venerable "old" Venue 8 Pro on eBay, and then found a used Venue 8 Pro 5855 (the newest model) in great condition for a fair price on Swappa. The 5855's upgrades include: 4 GB RAM, 1920x1200 display resolution, a newer Cherry Trail Atom CPU, a slightly faster eMMC (according to tests I've done with Crystal Disk Mark), and the Active Pen (an accessory but came with my purchase) which uses Wacom technology. My 5855 has 64 GB of internal storage (eMMC, not SSD).
I've only had it for a couple of days, but for those who may be interested, here are my impressions and findings so far. Warning: be reasonable in your expectations! An Atom processor will not match a Surface Pro in performance! But this new Dell is quite usable with Verbum/Logos, if you don't need the absolute best performance.
I haven't timed everything, but just from memory, most functions in Verbum (such as startup, passage guide, opening layouts) happen in about 20-25% less time with the 5855 compared to the older Venue 8 Pro. There is still some wait time compared to an i5 processor, but not bad. The upgraded screen resolution makes extended reading easier, at least for me. Indexing will take some time, but that's a given. WiFi works well.
One interesting glitch: I had used Touch Mouse Pointer with my old Venue 8 Pro, and found it helpful. Something about the configuration of my 5855 doesn't let Touch Mouse Pointer and Verbum play nice together. Some functions (opening layouts, entering reading mode) lead to weird glitches.
That's where the Active Pen comes in. When I disable Touch Mouse Pointer and use the Pen as a mouse, the glitches disappear. I have limited experience with digital pens, but this one seems to work very well - for left or right clicking, highlighting, or drawing (in other apps). If you go 5855, get the Pen. My bundle also came with the Dell Bluetooth keyboard which matches this device in size. It doesn't attach to the 5855 or its cover, but it can sit on the open cover well enough to be usable for the limited times I will need it with the 5855. I have my laptop for heavy digital lifting, so that isn't an issue for me.
I haven't had my 5855 long enough to get a good sense of battery life. Installing and indexing and setting up various apps eats up battery fairly quickly. Some reviewers say that the 5855 has a 5-6 hour battery span. That looks reasonable based on my experience thus far, but my sense is that it could go a bit longer without much trouble.
One accessory you will want with a 5855 is a USB/USB-C adapter. The only USB port on the 5855 is USB-C. None of your "older" USB devices will fit in it. So, either buy new flash drives or whatever, or an adapter!
I posted this for anyone who is interested in using Verbum/Logos with an 8 inch Windows tablet. The display may be too small for some tastes, but it's very portable. It's bigger than most any smartphone display (so far!), so size is relative!
Feel free to post questions, and I'll answer to the best of my ability.