I've tried riding a Strida. It might be OK for short distances on smooth pavement at low speed. Like the Description says, you'd use it as an ultra-portable bike to carry on public transortation.

My Xootr Swift is not heavy or expensive, and does not look awkward. It folds up small enough to carry onto a train as long if it's not crowded. The bikes that fold up really small are $1k or more.  The problem with most folders is it can be hard to add on racks, fenders etc, because of non-standard frames.  The small wheels are not good on bumps.

BMX bikes are for doing tricks, or at least looking like you do, not serious transportation. You can't peddle one over 10 Km/hour and they'd kill your knees if you tried to ride very far.