I've got 2 pairs of 50/50s (both X and the sealed XX pedals) and they're fine.
Minimal maintenance is required, of course, but you should factor that into your thinking anyway - you're getting into racing-level pedals, and like all top-end stuff, maintenance is required.
That said, the only
real issues seem to be the pins.
If you add a little extra Loctite (blue) then they seem to hold much better.
You can get the extra-long silver pins (they come with short silver pins, which are fine - for cruising!) which do stay put better, but might not be aggressive enough.
The 5/10s will help a lot, though.
I've ridden Straitlines, but not owned them.
Look awesome, will KILL you shins if you whack them - but have reportedly poor life in the wet/mud.
BUT, I've read they've updated the bearings (now 100% Igus IGLIDE Polymer Bearing System) and that's supposed to have cleared things up.
Universal Cycles in the US have some 50/50xx's for about $65AUD (only Gold/Black:
http://www.universalcycles.com/shopping/product_details.php?id=7031).
Even including air freight, that's well below local pricing.
I got one set from there, reliable source.
Finally, I can also second the NC-17 pedals (see Chain Reaction Cycles).
Used them in Germany (mud...) and they were great.
Light, too - over 200g lighter than the competition (Sudpin III).
Just a thought