I've owned a Microserver since its very first versioncame out.
I can totally relate to a missing m.2 or internal USB3. Though there's one thing that I am missing even more sorely: video output.
Hear me out: I know we're talking about servers.
But the CPU-makers have understood that there is a necessity for graphics. So, even the Xeons have an iGPU. In fact, looking at the E-2 lineup, more than half have one! But what's the use if HPE didn't add the traces and a connector on the back? Wasted potential!
Look at the "normal" Gen10 – yes, it was aimed at digital signage, but how refreshing to have the *option* to drive a display. Heck, even two 4k at the same time! You don't _have to_ if you don't want to, you can just as easily run a headless server. But it's there in case you need it. Just like I don't believe that every single person buying a Gen10+ will use it for virtualization: How much effort (and cost) is lost on having four RJ45? The people who really use those probably aren't happy either – they'd rather prefer faster ports…
I believe that the Microserver was and is aimed at the SOHO enthusiast crowd, as a low-cost entry system flexible enough to be used in multiple scenarios. Once you figure out you need a more specialized server, you'll know what exactly you'll need; for the time being, the Gen10+ is your general-purpose server (without having to invest too much).
As such, a decent "boot drive option" is as bad an omission as "a video connector". I can understand that a PCIe connector had to be cut (probably due to size constraints), but that's OK if everything's on board (and PCIe bifurcation is available, which it is). Wasted potential. And still: It's the best option I can find on the market if I want a decent value, high quality product that I can just buy, throw a bunch of drives in, and just have it run.
The perfect machine just doesn't exist. Truth is, I'm still running my N36L because of that. I actually need to be able to connect a display (and have it show more than just a terminal). After finding reason after reason for skipping the Gen8 and the Gen10, I finally got myself a Gen10+. It's not perfect, but it's still very, very good. And it's the best option on the market right now.
Well, yes and no.
For the digital signage role you could've easily just used a thin client - the HP t620 Plus can drive 2 Displayports by default, while the t730 can drive 4 at a time. Either devices are less than 200 USD on eBay, and I doubt that you'll need a quad bay SATA setup to drive something like that.
I went with a t730 to upgrade my N40L (interconnected to the t730 using Mellanox CX3 40GbE). This would yield something similar to a Qnap TVS473e (an 900 USD 4 bay unit with a similar AMD APU and capabilities.)..if you factor in the price of a used t730, an old N40L, the 40GbE cards+Twinax cable, its about 450 USD. Add in about 3 years of power consumption from the N40L+t730 combo (more than the Qnap) and it's about even money versus the TVS473e. The newest t740 would also make for a decent drop-in upgrade, but mine has not yet been delivered so far.
What is useful however in the SoHo server context is something like Intel Quicksync/AMD UVD in the processor, which can help on transcoding tasks common in home media center and/or professional video situations (like DVR playback/search for security camera streams) - its present on the Pentium G5420 SKU but not the E2224 (but is present on the E2246G). You should not need pinouts to take advantage of that.
As for the quadport NIC, that's actually useful in the context of the MSG10+ since Intel didn't skimp on the NIC used - the i540 can actually do SRIOV/VT-d on-card, and I am pretty sure SRIOV will work right out of the bat if you have the E2224. It's then possible to run several VMs (one being something, like, say, pfsense), allocate PCIe VFs via SR-IOV to each of the VMs and then have them do networking at nearly line speeds since the hypervisor will not need to flip packets between virtual NICs. Even for a gigabit NIC that's super useful.
My beef with HPe is that they are crippling an otherwise decent design to force market segmentation. For example - FreeNAS will not function with a USB2 USB drive as its boot media since version 11.2 - but yet HPe decided not to give the GS10+ internal USB3 bays or equivalent internal storage options (M.2, even if it's M.2 SATA would've been nice here, or paired MicroSD supporting something like A2/V20 speeds). Instead of leaving a server out on a shelf at a branch office I would have to lock it in a ventilated closet to keep, say, some sales guy from "borrowing" the USB boot drive (instead of having it secured within the server itself) that is out in the open...which limits its deployability (well, the same sales guy could also yank out the power brick if they lost their laptop charger and need some juice before a sales meeting, for instance - really need a locking mechanism, HPe). Then there is the 2 RAM slots (4 would've been super-useful), or shrinking the chassis down without much benefit in return (besides it being smaller, but that messes with internal airflow i.e. inability to take a larger, slower fan). At least the old G7/G8/G10s have an optical drive bay on top which can be used to host a boot drive. Sure, they are cheaper than their peers but its flexibility is so limited compared to, say, Supermicro SYS5029D-TN4T (1200 USD but a 3+ year old design) or a Qnap TV-677 (much newer, and around 1500 USD) that I don't think it's that great of a value. As
@Patrick says, at some point you are better off with a Proliant full sized tower server instead.