the only thing that I think about is support......since they came out with the d2pro9 which works for the olders wii's also... apparently support wiikey may stop .....then you would need another chip.
now the d2pro9 is more expensive now then it will be in a few months time....
so if you did need a new chip in a few months...it would probably be less $$.
guess what I'm trying to say is....it will in the long run if you had the d2pro9 to begin with....it would probably end up costing the same if you got the wiikey 1st and then upgraded to the d2pro9 in total at a later point.
also this is under the premise that support will stop for the wiikey..as rumour has it.... true or false...no one but them knows
d2pro9 a much better and versatile chip than wiikey and it uses Intelligent Code Modification which makes it totally stealth... where the wiikey is not really stealth.
best I can tell you.....