I decided to dip my toes into Eurorack and the Hysteria was my first choice as a VCO. It is really simple to use and calibrating it is extremely easy. I think it sounds great and it's nice to have an analogue VCO.
Pros: Nice sound, can modulate waveform and pulse width. Sync is possible and it can send a pulse, which can be used as a clock for something else. The quantiser also works very well.
Cons: In some ways it's a shame that there are not separate outs for the different waveforms. However, then it wouldn't be possibly to modulate between them. There's no sub, so that might be considered a negative if you want more bass.
Overall, I think it was a great choice and recommend it to anyone looking to get an analogue VCO.