I won't be much help, either!
I guess the question is how much drum replacement are you doing now?
My general rule on plug-ins is to only buy something if I need it to finish a project. But I don't buy all that many, I think the last thing I paid cash for was Melodyne, and that I bought the 'Uno' version, then the plug-in. I was working with bands that were close to being really great, but the occasional bad note was killing me. So I broke down and bought it. Great investment though, as I use it for at least a couple of notes on almost every mix project I get!
If it's just for fun, I'd lean towards the tape sim, if you love it that much.
If it's a business decision, I'd put the money away until a project shows up with some unsolvable problem.
If it's an educational/skills thing, DRT might be best, as it'll let you start learning the drum replacement techniques, etc.
I still use Aptrigga, for the occasional drum replacement that I do. But really, 90% of the time, I don't use it, except for a kick drum that just doesn't have 'it'.
The only third party plug that I really couldn't do without is melodyne. But I haven't experimented with Reaper's pitch correction, maybe I could get by without melodyne, too!