I use the Modal Cobalt 5s alongside the Microfreak. While the Microfreak is my go-to for strange and experimental sounds, the Cobalt excels in delivering classic analog tones. The Cobalt is my preferred choice for rich, warm sounds, but it also handles modern and dynamic patches effectively, thanks to its extensive array of oscillators. The sound quality is the synth's main strength, making it stand out among the vast variety of hardware and software instruments. Considering its price, I believe it's the best inexpensive hardware synth you can buy for retro and analog sounds.
The build quality is solid, and despite its compact size, it feels robust and well-made. It has some weight to it, especially compared to the Microfreak, making it a bit less portable. The biggest downside is its keys—they work as they should but feel a bit clumsy and not very pleasant to use. While this is not a dealbreaker for a compact and inexpensive synth, it might affect its use as a substitute for a MIDI keyboard. Another downside is the limited built-in effects, with only Chorus and Delay available. Both are excellent, but there's no dedicated reverb effect, so keep that in mind.
Overall, I love everything about this synth except the keys, which I tolerate. It sounds absolutely gorgeous and, with the Modal App, offers a very convenient workflow inside the DAW. If you already have other synths or a decent MIDI keyboard, consider going for the module version of the Cobalt. This is what I would have done if the Cobalt 5s hadn't been one of my first hardware synths.