Regen: Level 4 Quick Recovery. +30% recovery
Bio: Level 1 Inexhaustible. +25% recovery, +add'l 10% with Efficient Adaptation available at level 10.
Radiation: Level 1 Gamma boost. Complicated recovery that's based on your hit points, don't know what it cashes out to.
Bio at least is pretty straightforwardly better. You're right that most other sets don't come in to their endurance tools until more like level 16 or level 20, but also level 4 is in fact too early -- nobody has endurance problems at level 4. I tend to find that endurance problems come on in the late teens.
Again, back in the day, these powers would come later -- you'd get them at level 28 or something, and in particular I find that the early 20s, when you often have bad end redx slotting, are a brutal time for endurance. But with the earlier primary/secondary powers of a few issues ago, Regen's advantage has again eroded here. And while in some cases those powers do come late enough that there is a slightly awkward gap, it's also the case that they are mostly better endurance tools than Regen's pretty small recovery bonus.
Even for a newbie, the first 20 levels go pretty fast.