NinjaCool; I'm not deeply into these KO transmitters, but I'm quite sure that the Helios is backward compatible, since you have the option of "Mode settings", where you can choose Advanced, Super HSR, Normal. Look here: http://www.kopropo.com/EX-10_helios.htm
scroll down a little, look under "Others".
If I'm right, you might be able to sell both of your Mars, and this way getting money for the Helios. Personally, I find the Mars looks way better than the Helios, but there's more into it than just looks :-)
Dont just take my word for it, try asking in the Helios thread.
Lee82gx and onebeatuptc3: I also hear persons, who say there's aint any speed difference.
I know, that my current Presto have a frame rate, which is twice the Helios, thus my Presto should be much slower. But I would like to relate the improvement to something I know, like servo speed.
Can you guys enligthing me in a way I can relate to. This "it's better" is a quite wide definition