Thats correct. Users no need to worry about the browser it uses. LR is bundled with the supported Firefox version and users cannot replace/upgrade that one.Once you launch the browser with TruClient protocol, it launches the required browser available within LR.
Unfortunately an old version of Firefox is used. Firefox 3.6.3 is an old browser that is not always supported by websites. The Ajax Truclient plugin does not work with newer versions or with IE. This makes Ajax truclient useless in some projects.