Did some testing and played around with the software of the following 3:
g2x (datalinkII)
traqmate (traqview)
dl1 (rt analysis)

Here is my humble review:
1) g2x:
looked at their demo sample run... but at least for me it was not very intuitive, I personally did not have much success playing with this software. Lots of buttons all over the place, does not look too great.. tried changing trackmap color display to longitudinal G's and set some thresholds, but I didn't succeed. Maybe their demo run is stupid, only 2 laps, probably one warmup, one cooldown and no full lap in the middle... Stupid to include such a demo officially.
12MB zipped -> fairly large software, makes me think it is a bit longer around, but seems a bit messy

2) traqmate:
Looks much simpler, but also much more polished.
Once you find the setup button on the dashboard you can play away with all sorts of graphs. Intuitive to use, looks nice. Pretty simple.
Probably sufficient for most of us with the benefit of ease of use.
From a software engineering perspective, I'd say it is the most modern. Different windows don't slow each other down and remain responsive when doing something processing intensive in another traqview graph window.
(people who program GUIs will know what I mean)
Bottomline: I really liked it.
People having trouble with red/green colors when displaying thin lines, may have a hard time seeing the brake turn map (colors can't be changed)
2.6Mb -> still very small, probably fast evolving software, I'd say pretty new, and at this size, it's easier to give this polished feel.

3) dl1 RT analysis:
22Mb -> the largest software of all 3.
This software is the most customizable to the point where I say WOW.
For me it was still easier to make nice plots right away as compared to the g2x software. I think it is pretty easy to use, with very clean concepts (variable manager, run manager, xy plots, ...)
But it takes maybe slightly more work to set plots up then with traqview, because you have more options to pick.

And the amount of features is just astounding. As an example of how complex of things you can do: I didn't like the brake flag map and immediately was able to define a set of 3 user variables with some equations containing "if" conditions and got a special colored brake/coast/accelerate map.
You can also change colors, totally customize all you plots, draw track markers, click into the trackmap or graphs to get the data points... (clicking into the trackmap didn't work for me with the traqmate's software which uses a slider instead)

This software is IMHO by far the most powerful, but it helps if you have some data experience yourself. If you don't like playing with data too much and just want to click on "brake turn map" to see something predefined and unchangeable, better go with the traqmate software.
If you on the other hand like to customize things and display your own wildest ideas of graphs or customize them, this software rocks.

Downside obviously is the price of the dl1 compared to the traqmate.