I definitely think the 30 minute clock is too long but I'm sure there's also a few who'd prefer it even longer.
It won't stop me playing anyway so it's obviously not that big a deal to me.
Simon is pretty good at structures. i prefer 6 max tournies as its a far more skillfull game than full ring but too many end up being crap shooty at the business end of the tourney.
Being good at structures is nothing to do with it to be honest. A structure is designed to make a comp finish when you want it to. If you're good at structures you get it to finish at the right time.
The reason I'd prefer a shorter clock is because I'd prefer the comp to finish sooner.
With a 30 minute clock it will probably finish about 4am at level 20 or something.
Make it a 20 minute clock and the same comp is finished at 1.00am which would be my preference.