Really glad someone asked this clearly because so many people are confused between these options.
Your breakdown is very accurate. Self drive sounds attractive but honestly the reality on those roads is very different. Even experienced city drivers find it stressful. The ghats near Kedarnath and the narrow stretches before Badrinath are not forgiving.
The tour package vs private vehicle debate really comes down to group size and flexibility preference. Packages are good but you follow their schedule, their hotel choices, their pace. With a private vehicle you are in control completely.
One thing I'd also suggest is checking if the operator has done these routes before. Not every vehicle rental company has hill route experience. Before booking just compare Delhi to Chardham tempo traveller rates from two or three operators, the difference can be significant and you want someone with actual hill driving experience, not just city runs.
Registration reminder is gold, please don't skip that step
