The reservoir itself hasn’t changed.
It is still a plastic container with a couple of fittings and a remarkable plug:
It looks exactly like the standard plug on vodka bottles I remember selling ages ago in the USSR. This plug isn’t very handy because the diameter of the opening is too small. There’s a problem with control over the coolant level, too:
How can you control anything if the tank has a black front panel with a narrow strip of translucent plastic in the middle? All the modernizations boil down to the universal adapters:
…and to the ?-inch fittings included into the kit. There’s no sense in purchasing this reservoir as it is useless functionally and doesn’t improve system performance (as you will see in the Tests section). Thermaltake is surely aware of that and also offers an excellent expansion tank called Water Tank:
It can be placed on the side panel of your system case instead of an intake fan. The company also offers the AquaBay M1 panel that occupies two 5.25” bays, looks good and combines a Water Tank with a Flow Indicator:
The AquaBay M3 is inferior to the M1 in every aspect, particularly in the quality of manufacture, appearance, and functionality. I guess Thermaltake should stop producing the third model as it looks miserable next to the other components.