The Boxster is much more civilized than the Miata: power top, (partially) power seats, etc. So for cruising I find it better with a solid feel.
But I love Miatas: handling and light weight are tough to beat. Plus it is such a basic car that I have no fear doing work on it myself - replaced radiator, changed suspension, removed A/C, drilled out and upgraded front sway bar mounting brackets, upgraded muffler,... And autocrossing a $5000 Miata is so fun, particularly beating big money cars.
But the more I drive the Boxster, the more I'm tempted to get some RE-71R tires and give it a go.
