Most of the generic (TAPCO, ATI, et al.) action wrenches are cast from soft metal and finish-machined, and the pins on them used to tighten most float tubes will bend and break if you even look at them funny. The DPMS multi-tool, on the other hand, uses hardened steel pins pressed into the tool, and they will last for a good while.
I tend to use the PRI wrenches for float tubes (since I finally did manage to break a pin on a DPMS multi-tool after assembling dozens of uppers) and the DPMS multi-tool for just about everything else.
I am also very partial to the DPMS upper action block design, since it's easy to use and provides good support for the upper receiver.