Of all the Piper twin products, the old twin Commanche is about the only one I'd ever consider....but I've never flown/owned one to tell you for sure.
A year and a half ago, I traded my Bonanza off for a C340. I love the cabin size, comfort, and no more having a hose up my nose, etc., but it doesn't really fly "fast" until it gets way up into the flight levels.
An older, normally aspirated C310 is faster up to the teens, and the T310R will outrun it regardless of the altitude, but there's something really nice about pressurization.
Around here, density altitudes of 9-10,000 ft. are common in the summer and MEA's of 12,000+ are just about everywhere in/out of here, and to get above most wx, takes something that goes well into the 20's, which are a few of the biggest reasons I bought a turbo-charged/pressurized airplane.
But it comes at a price. Fortunately, my last annual in November was cheap (cost of the inspection and a few nuts/bolts that didn't add up to much $), but that's not the norm.
Twins just flat cost more money, and the time savings doesn't always add up to more than a few minutes on an average flight. It's heady to see 200ktas on the GPS unit, but on short legs (you stated you only fly in FL), there isn't much time savings between that and 160 ktas.
A shorter preflight, quicker warm-up, mid-field takeoffs/short field landings, and not having to wait the 5 min. to let the turbos cool down after you land can wipe out alot of the in-flight time savings.