Just an update- I had posted my pre-purchase concerns a month or so back regarding the image quality in the transcode process, with a comparison showing the de-interlacing issues on SD source material on a Tablo Dual (something not experienced, for example, on a TiVo Bolt).
After some continued use, and upgrading my FireTV to a more recent stick version, I've found the video quality overall to be very acceptable- nearly on par with the MPEG recordings on TiVo. (720p60 resolution is not an issue in most displays or devices with good upscaling technology). I'm not seeing mouse-toothed edges on angular straight lines, as experienced on SD source material transcoded on the Tablo, nor other examples of color smearing or other artifacts.
Despite not having commercial skip functionality of either Tablo or TiVo, the shuttle functions are responsive enough that it's a good approximation of the TiVo "skip ahead" behavior on TiVo. Program scheduling is actually easier using Alexa, although Tablo offers better tools for resolving recording conflicts. Tablo still has an advantage on the variety of device apps in play, also that video playback doesn't require the active use of a tuner.
That said, the Recast appears to be a worthy alternative. As a Prime Day discount purchase, it's proving out to be a very good value.