Hard to say. There are quite some differences between the two, so I'd say it is a matter of preference. Lemme see (this is from memory, so someone correct me if I'm wrong):
WODE:
+ plays most or all games
+ loads from USB
- costs more (about 80 bucks?)
- requires opening your wii
SWISS:
+ cheaper (especially if you buy an sd-gecko)
+ not needed to open your wii (just plug it in the correct slot)
- no USB (either SD or IDE)
- game compatability isn't perfect (yet?) (note: this is kinda hard to say...the
compatability list is rather blank)
There are more quality-aspects about both (user friendliness comes to mind), but I can't compare those without having actually tried either. But all in all, I'd say both are very valid products.
It has to be noted that a comparison is also quite unfair at this point, as swiss is still very new. Updates are coming out on a very regular basis, and rumors have it that its future might be even better (heard about an USB-gecko or even the front SD slot
possibly becoming available).
Personally...I'm still waiting for that sd-gecko to arrive by mail, so my preference is clear. It's partially because of the cost, but also because I like seeing a program comes together. Knowing myself, I probably get tired of at least half the games as soon as I find out they actually work perfectly.