Thanks for the suggestions. I'm not planning on L2 for about 2 years, so I'm not sure which to get since it will max out on an I for now. I don't really care about altitude, but I might get the doorknob just in case. It seems like they are very similar rockets.
You are right --- they are very similar, and it might be a hard choice. At close to $200, it's worth thinking it through and getting the one that suits your needs.
It looks to me like the main difference is that the extra length and the extra fin on the Doorknob means it is about 25% heavier (122oz vs 100oz). The Doorknob can take 54mm motors (38mm and 29mm with adapters), while the Warlock can take only 38mm (29mm with adapter). Because of the weight difference, they probably cannot both fly on all the
same 38mm or 29mm motors (Doorknob might be too heavy for some motors that would work with the Warlock). So it seems like the thing to consider is what kinds of motors do you want to fly, especially if you are going to buy hardware, and what kinds of flight profiles do you like.
I haven't done any legwork or research on this myself yet, so I have no advice on which would be "better." Personally, I don't want to get too complicated or get into electronics at this point, so I don't want the rocket to go too high. And I'm also thinking I'd rather just go with DMS motors instead of reloadables at this point. So, once I get closer to deciding, I'm going to look at what kinds of 38mm and 29mm DMS are available and figure out what kinds of flights I'm going to get with a Warlock on those motors. Then I'll do the same with the Doorknob and the 54mm, 38mm, and 29mm DMS motors. That would be a good starting point for a decision, I think.
After that, I'd consider options for down the road. Both rockets could be outfitted for Dual Deploy after the fact by adding an AV bay. Both rockets will have more motor options if you go with reloadables. The only real difference in that regard would be you have the option for 54mm motors with the Doorknob that you don't have with the Warlock, but if you don't care for the flight profiles you would gain with those motors, you don't really need that option.
Another consideration --- will these rockets even fit in your car!
It seems like with HPR, the "Rocket Science" starts before you even buy the kit!