I am so excited for a Lispy systems language. Existing languages just don't do it for me, though I think Zig is the closest to being what I'm into. So much good stuff in Scheme48. Glad the good ideas are being revived.
Can recommend Gerbil Scheme. Although fair warning, still GC'd and (for now) only type-annotated, not (100%) statically typed. But stdlib-wise and compilation-wise still way more "systems-bent" than most Schemes out there.
Haven't, so no hard "comparison" results to offer — but Gambits libs are included in Gerbil and readily importable or some of them (maybe all? dunno) auto-imported, and Gambit is Gerbil's compilation foundation essentially AFAIK. Where it differs from or expands upon the Gambit basis is "our own macro expander" (haven't particular gotten into that area of understanding yet tho) and the extremely-modern-real-worldish stdlib (http, json, actors, db driver bindings etc), perhaps other aspects too (ie. might cover further SRFIs beyond what Gambit does, dunno for sure though; ie. the FFI might be beyond Gambit's or not, again I wouldn't know).
I welcome any and all experiments in the low-level programming space, and writing a good one with Lisp syntax is an obvious approach. Carp (mentioned in the article) was a good start, but seems to have stalled out, and while it's easy to see the advantages of bootstrapping from an ML language, I view it as essential to the philosophy that the compiler itself be in a broadly-compatible Lisp syntax, compatible, that is, to the resulting language or sub-language.
But I also think it will exacerbate an existing problem with C, namely, macros. Low-level programming is all about knowing exactly what's going on, and since C has a preprocessor, that's more difficult than it otherwise would be. Just because something looks like a function call, doesn't mean it actually is one.
Schemes have a much better macro system, and that will simultaneously make the core issue both better, and worse. But it's very much worthwhile to try it, imho, and see if good tooling can ameliorate the downsides, while still enjoying the power, and freedom from tedium, which macros bring to the table.
Can recommend Gerbil Scheme. Although fair warning, still GC'd and (for now) only type-annotated, not (100%) statically typed. But stdlib-wise and compilation-wise still way more "systems-bent" than most Schemes out there.