2tRAC is good on the server to test/configure. Like adding preferences, managing the organization, building workflows. It skips the web tier/server manager so you don't have to have those working before you can connect. So for administration the 2tRAC is handy. And some integrations require the 2t like on the Dispatcher Module for certain NX direct translators.
However, I would only use a 2t for server-level things because 4tRAC outperforms 2tRAC even at low latency (anything higher than ~1ms). 2t is VERY dependent on low latency to the DB server as anything above 20ms starts seeing serious performance degradation which is why the 4t architecture was introduced. The reason that 2tRAC has to have the binaries is because it connects directly (hence 2 tiers) and acts as both server and client. Whereas 4tRAC communicates through HTTP (Web Tier) and is therefore latency tolerant up to 300ms and still performs to 400ms with a lot of degradation.