I started working on my project (post 1 and post 2) about a month ago. I had a bit of experience both with Xilinx/Amd Zynq SoCs as well as Altera/Intel Cyclone V SoCs. While working on the 7 Ways to Leave Your Spartan-6, I was able to explore the Spartan-7 FPGAs and improve my knowledge on the Xilinx toolchain.
First, the fact that I can work with either a Spartan-7 or a Zynq on the same toolset, without any significant learning is honestly amazing. Just this fact allowed me to use one of my boards running PYNQ, to test how things like DDS compilers work in LUT mode, play around with AXI block memory controllers, etc. I have also seen this from another perspective. For example, I want my project to be used as a tool in an optical laboratory. Hence I would like the connectivity as well as the interfacing to be appropriate for such a setting. This means, that USB cables are not Ideal (both reliability and expandability are not the best) and as such, I would prefer something like ethernet. Since I have the ability to relatively easily swap platforms, I can move from Spartan 7 to Artix 7, Zynq 7000 or even UltraScale (e.g. Kria).
Secondly, I have run into some trouble with sharing projects. Sadly, this is something, that needs quite a bit of improvement (at least in my opinion). I have seen a lot of software provide automatic version control integration (e.g. Altium, Fusion360, etc.). Having a reliable version control with Vivado is still something that I am struggling with. I know that there are options to create .tcl files, but the fact that I have to collect all of the files, create a file structure and edit the .tcl file just seems tedious. In addition, If I make big changes to the project, I have to redo everything. Another thing, that bothers me a bit is the fact that some features are a bit hidden. For example, If I want to access the pin planer in Vivado, I can either click on the Schematic button in the RTL analysis tab or the Synthesis tab. It is unclear which one should I choose. Personally, this is done much better in Intel Quartus, where the pin planner is located in the toolbar and it also has a keybind by default. I also find that some of the menus can be rather confusing.
Thirdly, I remember that a couple of years ago I was looking into buying an FPGA. I decided against it since all of the documentation/information looked quite complex. It seems that in a couple of years, a lot of beginner-friendly information was published on the internet. Additionally, there has been a lot of hardware developed for hobbyists (the Arty boards from Digilent are an excellent example). All of this together makes an FPGA a compelling choice when working on a project, where not everything is known. For example, In my project, I did not know how I would send out information, how quick I would collect samples, which communication protocols I would use, etc. I did not have to worry about anything since FPGAs can run at even a couple 100MHz, which is much much faster than anything I was aiming at. Additionally, if I wanted/needed an additional communication port, I could add it however I wanted... Just the flexibility alone makes FPGAs worth the extra price (in most cases).
Lastly, I have never worked with MicroBlaze, at some point I even avoided it as much as I could (programming in C is scary). Furthermore, I always thought of non-SoC FPGAs as relatively useless for my experiments. I have to say that I have completely changed my mind. I do have to say that getting into Vitis can be overwhelming at first. But when I got the hang of what Platform and application projects are, everything became much easier for me. I can say that I have spent quite a bit more time getting my Blue Pills and Maple Minis to work compared to an Arty S7 with MicroBlaze. Additionally, the Confluence examples were extremely useful to the point where I was almost able to kitbash most of the project.
To conclude, the Spartan-7 FPGAs have found a place both on my workbench as well as on the list of devices that I might use in future. Sadly I haven't yet found any convenient modules with the Spartan-7, except for the CMOD-S7. Hopefully, these will appear soon enough. All in all the 7 Ways to Leave Your Spartan-6. I liked working with the Spartan-7 devices. Additionally, the whole community provided both information as well as inspiration for many people looking at starting their FPGA journey.
Best regards, Jure