Well, for starters, you have different units on those two maps, which makes things a bit more difficult, but, i'll give you a general overview.
The vertical axis is pressure ratio, meaning how much the air is compressed. Here a ratio of 2:1 means it's compressing the air to twice the normal density, giving you 1bar of MAPressure.
The horizontal axis is actual flow. The TD04 map is in cubic feet/minute (CFM) while the T3 is in LB/MIN. This makes comparison a bit tough between the two maps.
The lines that are curving across the middle of the map are turbine RPMs.
The lines enclosing area on the maps are efficiency rates. If you look on the TD04 map, you can see the percentages written on the map.
Now, reading the TD04 map, we see that peak efficiency is 76%. The area enclosed by the 76% line includes all of the area in which the turbo is operating at peak efficiency. That said, the most you can get out of the TD04 at peak efficiency is about 0.9bar of pressure and 225 CFM of flow.
The T3 map is rather crappy. While we can still tell where peak efficiency is, we aren't quite sure exactly how efficient the turbo is inside that area. You can, however, see that you can run about 1.25bar of pressure within peak efficiency and flow around 25 lb/min of air.
A direct comparison of the two turbos can't be accurately made with these two maps because a cubic foot of air will weigh different amounts depending temperature.
That said, you can push the turbos out of peak efficiency range. You'll heat up the air quite a bit as you move farther out on the maps though.
One last thing youc an tell from the maps is what the turbo is capable of at certain rpms. If you follow the rpm lines across the map, they show the exact CFM for a certain pressure at a certain rpm. For example, on the TD04 map, there is a point included that shows that with the turbo spinning at 150,000rpm, the turbo will push out 360CFM at 1.0bar of pressure. This also puts it in the 60-65% efficiency range. (bad)
Hope this helps!
Now...what we need is a compressor map library!