A number of folks on the DIYstompbox forum have built decent-sounding units with these, and I gather Belton/Accutronics sells tons of them to amp makers producing lower-cost practice amps with on-board reverb.
Of course, unlike actual springs, these will not behave differently depending on how you push them. To some extent, one can design in the qualities one wants in their solid-state reverb by selecting which of the 3 modules they use, and shaping the tone via filters/EQ. Note that, internally, they are essentially a couple of PT2399 delay chips and some passive components; which is why it's a larger epoxied module rather than simply a chip. That's not to diss it in any way, because it IS a clever idea. But reverb can often be such a personal taste, much like distortion, and the idea that everyone's tastes can be addressed with 3 different modules is, well, limited.
That said, they don't go "boing" when you move anything around or knock into the chassis, they are conveniently small, and pretty inexpensive, and don't require more support circuitry than an actual spring does.