I had both (until last month when I said good-bye to the 996TT). The torque on the TT felt very raw and scary fast, while the supercharger pulled like a freight train in a smoother/linear controlled manner.
The SL55 gets driven more due to the vert fun factor. I'm 36 y.o. and the last time I checked there was no age limit or nor restrictions to owning either one.

The negative: Both depreciate like crazy! The TT is easy to mod, while the 55 is actually nice stock.

 

own the 911TT and my cousin owns the SL55... so i've had plenty of exp in both... for a daily driver... go with the SL55... it's more luxurious, and easier to keep stock... guarantee you will get the mod bug with the 996TT... next thing you know, you're tracking it and doing turbo upgrades...you get my drift... if you're into doing some mods and looking more at the performance aspect of it... 996TT is a no brainer.

 

I'm having this exact same dilemma, Thanks for making this thread. It looks like the SL is the way to go.

 

I recently traded my E46 330Ci for a 996TT and I couldn't be happier. I am very happy with the build quality and the power is just monstrous...and it's stock . Granted, I didn't consider an SL55, but I think at this point in my life (I'm 34), a Porsche Turbo seemed like a better fit. As far as maintenance goes, the Turbo's version of the 3.6L is pretty much bullet proof--I think either car, as long as you maintain them as you should, would be a nice ride

 

sl55 too heavy, rattle when the top is down, supercharger some time doesnt boost when the fans are not on. tt is the right choice

 

Haven't owned an SL55, but have driven one several times. Fun car, a little less sporty, but definitely very quick in its own right. Realistically, you probably wouldn't want to take one to track sessions if you're into that sort of a thing.

Also, if you're planning on keeping it for a while, the Turbo has a more timeless design whereas the SL55 is probably going to end up being just an another old Benz - think of the feeling you get when you see a 10 yr old SL vs. a 10 yr old Turbo. The SL is loaded up with electronics which my cautious side tells me might be more prone to failure and if so more expensive to fix. The Turbo feels a little more mechanical, but don't know for certain.

 

I looked at a few SL55s, they sound great, and the power is very linear! ECU/pulley upgrade achive good hp gains. But the experience in a turbo is very different, more involving and I actually enjoy modding, so it was a no brainer.

 

I own a 996 Turbo w/mods, E46 M3 Comp w/mods and I'm looking for a SL55.

IMHO the M3 is a great daily driver being RWD w/linear power.

The 996 turbo is scary fast, very low, needs attention and attracts too much attention.

The SL55 is a luxury screamer drop top that seems to fly under the radar.

Personally I need all three, but would choose the SL55.

 

I drive around on weekends looking for SL55's to beat up on haha

 

Me too, but I'm not biased...I'll beat up on anything...

 

plenty of seat time with both. i would go with the sl55. my reasoning is as follows:

i'm 36y/o and the porsche is a dream car from way back. i got into a 996c2 as my first porsche in order to 'test the waters' before i plunged into a 996tt. figured i'd allay my fears that the car is gonna cost me a fortune to maintain, prove unreliable on a dd use, and be difficult to dd.

what i found with my 996 is that the car is a pain to dd because parking is a problem, it's loud, stiff-ish ride, routine maintenance is high, car needs very precise alignment, and tire appetite is verocious. the 996 is very reliable but running it is not cheap. a 996tt demands respect and attention. i love the looks it gets for sure, it's a crowd-gathering car, and the reliablity is really fantastic.

the sl55 is an awesome driver with great steering, great ride, silence, luxury, and less maintenance. basically the sl55 will likely be as fun to drive but without the the hassles. so it wins in my book. only problem is, if you seek attention, the sl55 is a wallflower whereas the 911 is a statement.

everybody should own a 911 when they're young. an the 996 series is a fantastic used car value. if you never had a 911 before, and you're up to living with it, then you should treat yourself just this once. if you want the best car though, the sl55 is clearly the choice.

 

classic

 

an sl55 will do the creamiest burnouts you could ever want and it will power-on oversteer at will. this makes it a super-fun car to beat on. these are things that a 996tt will certainly not do for you.

 

I DD a 996TT...with a suspension upgrade (pss10) the ride is really very comfortable while handling is very flat, etc. Torque is addictive...2 + 2 seating is sometimes helpful...AWD makes this a four season car anywhere, and great in the wet...owning a Porsche is alot of fun. Downside: tires are expensive and short lived...interior noise is an issue, be sure to test drive before you buy...speeding tickets (get a Valentine). If the interior noise is not an issue, you will love this car as a DD, IMHO.

 

bruceinmiami,
I totally disagreed with the age thing with Porsche. I got my first Porsche when I was 21, first 911 at 25; and I'm turning 50 next week and still driving fast. I wouldn't say SL55 is for old folks, but for the people who wants to SLOW down. Age has nothing to do with what you drive, it's the mind.

ps. I saw a 70+ year old man driving a speed yellow GT3 the other day.