The memory on the CS200 is very useful. You go for a ride to a mate's place, hang around drinking beer for a few hours, ride home again - both rides can be stored in seperate files or the whole thing in the one file (to hide the evidence of the beer drinking
). At the Tour Down Under, I had one file for the trip there, another file for the local running (about 20km over the day as it turned out), another for the trip home - three very different trips (as it was largely downhill there, hence largely uphill home, plus pouring with rain on the way home, plus the pottering around while there didn't mess with my long run figures).
Wireless is very good. I have experienced none of the interference that some people talk about and I think that's related to where you place the main unit, it goes onto the bike quickly and easily and you don't have to keep messing about with the wires. Having said that, I've got bikes with wires everywhere and they don't annoy me that much, just look ugly. But wireless is definitely better.
I tried buying cheap, looked at other options. In the end, the things are pricey but unless it stops you buying food for a week, it's probably worth just taking a deep breath and buying the good unit up front. You'll forget the pain of paying for it fairly quickly, the missus a bit longer, but there aren't too many functions on the CS200 that I don't use (and, it should be realised, none on it that would prevent me riding at all if I didn't have them
)
A bike computer isn't like a good saddle - it isn't essential. It's like padded nicks for trips of an hour or so - a darned good idea but you can live without it. But, having decided to spend a bit of money, it's better to have what you want - the pain of paying for it wears off long before the frustration of the cheap unit not quite doing the job you want.
Richard