I voted for the 348: that's what I'm currently searching for. I love the 355, and think it's more beautiful than the 348 - I'm sure most would agree.
But although the 355 performs quite a bit better, it's also much more complex and therefore more expensive to maintain. Power Steering (I prefer manual for the road feel), Airbags with ECU(s), Electronic suspension, etc. And the F1 transmission and clutch are extremely expensive to repair. I think the hydraulic pump for an F1 transmission is over $10k by itself. Even if the F1 was bulletproof, I'd still get one with the 6 speed.
Also, there still seems to be a lot of ongoing concern & uncertainty on 355s regarding valve guide problems. Also have read of Ferrari techs finding severe ring wear and cylinder damage, apparently from undiagnosed exhaust header failures (cracking), causing mixture leaning in those cylinders.
I also want a targa top, and a 355GTS will apparently cost at least $30k more upfront than a similar-condition 348TS. I think the potential is there for 355 ownership costs to be double what a 348 would cost, although that's just an impression on my part... I haven't run numbers. Don't get me wrong... I'd love to have a 355 - I started looking for one, as I posted here a few months ago. But I'm retired and have to limit what I spend on a car, so finally decided to go for a 348TS instead. And speaking of that... I'm traveling back east next week to (hopefully) buy one! PPI done, and I'll post pics once I've seen the car and bought it.
More 348 input... FWIW... My previous neighbor has owned a 348 for many, many years, and it's set up to Serie Speciale specs, and he's added TR brakes and tracks the car a lot. He also owns a company that upgrades the Motronic ECUs, and his puts out around 340hp as I recall. He says he can easily keep up with 355s on the track. He is an expert driver, though, and has previously held driving classes/clinics (or whatever) for FCA in the area.
Also, for those feeling the need to upgrade looks of their 348... I've seen a couple 348's with 355 body panels... here's a link to one on Autotrader... Yes, it's a 348 (check the interior!) http://www.autotrader.com/fyc/vdp.js...=&cardist=1134
Take care! :drive: