IMO Jetstream runs not as black and thinner in 0.5mm as Schmidt ( I use them both in Parker compatible pens).

Those are the only two hybrid inks I use, and mostly the Schmidt EasyFlow 9000 because it is all of the above and smoother writing. I never use regular ballpoint ink, just hybrid and gel.

Pentel Energel makes disposable gel pens and gel refills from 0.4mm to 1.0mm in many colors, and they also make a hybrid ink (low-viscosity Vicuña ink) pen, the Pentel Calme. It comes in 0.5mm and 0.7mm (lots of colors are available) and the black is darker and deepe, actually black, like a gel pen level black, not dark purple like the Jetstream or Acro. Not refillable, I think.

Also Pentel makes another non gel pen called the Glidewrite which has another type of hybrid ink, TechniFLO, a super-low-viscosity ink and again is not refillable and only comes in a 1.0mm tip. I have no experience with this pen.