Not to derail the thread, but other than possibly the Klein -specific BB on the early bikes, there's no reason the "defunct niche brand" Quantum couldn't be brought up to 'modern' 10-sp, rim brake specs. Pretty much every other component is what would have been on any other bike at the time.
Off the rack? The Tarmac is a better performer thanks to ten more years of development.
And, since the BeikForums motto is "Practicality Uber Alles;" if the OP's mom is only letting him keep one bike; he should get rid of the Klein. Sounds like he likes his Spesh better, anyway.