i currently drive a 01 deville i will be getting a new car soon but i cant make up my mind between a 06 DTS or a 05 STS, i have really been leanin to the STS but ima afraid im not gonna be satisfied with a V6 and im going to have to go with the V8 but then again i have been in love with the DTS to ever since i seen a fully loaded one ordered for a customer before they hit the lots while i was gettin a oil change and it was the same color as my deville i have

from my experience .... i've had both the last 4 months .... a 05 STS 1sg for 2 months and now a DTS Lux 3 .... they are different cars .... i had not had a Cadi for about 10 years and was looking for that Cadi ride .... soft and comfy ... wanted a DTS but dealer couldn't find what i wanted so we started looking harder at STS .... the DTS had the right size backseat ... and easy to get into for our parents .... STS was not quite as big, but it would work .... first we had drove DTS ... it drove and road very nice ... didn't feel like heavy FWD and did not feel as big as it is .... first STS driven was loaded V6 .... it was pretty nice, but didn't like color .... so finally drove a V8 with 1sg ... it was much more like a euro-car in ride and performance .... if that is what you're looking for .... but we ended getting a different STS 1sg w/performance package .... much to our dismay , it road even worse ... but we hurried our decision because of my wife's pending neck/spinal surgery .... after surgery she couldn't take the bumps ... so we inquired about the DTS .... and of course , now they find the exact one we were looking for .... so away goes the STS ..... ouch ....

i would say it really depends on what you're looking for ... i feel the DTS is a more traditional Cadi for those who need lots of room and a smooth ride ...
and the STS is more hi-tech and performance oriented ... the new edgie Cadi.. just my 2 cents ....

Keep in mind when making your decision that the "new" DTS, while a substantial revision, is still based on underpinnings from an over 5 year old car. The STS is the better performer, has RWD and offers AWD as an option for those in colder climates, and being that its Cadillacs technology showcase, it really has more technogeek options in it.

The DTS wins mainly in the fact that its the last caddy produced that provides that soft ride Cadillacs are known for, and has plenty of interior room. The new interior is very nice, and the car finally features some highly desired options like Xenon headlamps, heated windshield washer nozzles, and heated and cooled seats.

As davc says, these are two very different cars. A few months ago I drove both the DTS Performance and STS4 1SG back to back. (We drove the STS V8 regular suspension a year or so ago.) He drives a Lexus GS 400 now, and generally leans toward the RWD import sedans.

Much to my surprise, he greatly preferred the DTS. It's simply smoother, quieter, and roomier. It doesn't handle as precisely or with as much balance at the limit, but few people drive cars this large that hard. His other car is a Mazda RX-8 that he drives hard enough to get awful fuel economy, but he wouldn't drive these cars the same way.

So I guess it comes down to driving style. The STS 1SG feels quite European, as davc also noted. Very firm and taut, with a relatively tight interior. The DTS feels American, but with the float and other bad manners of previous DeVilles nearly eliminated. It drives very well up to at least 7/10. Much better than the old DeVille even in DTS trim.

The regular STS falls between the two. Ride quality is much smoother than the 1SG, but it doesn't feel as "tied down."

A further possibility is the Buick Lucerne CXS. It drives much like the DTS and costs about $12,000 less even after adjusting for feature differences (my site www.truedelta.com performs such comparisons unlike any other). Many DTS features simply aren't available on the Buick, though. I think anyone considering the DTS should at least check out the Buick. Just ignore the CX and CXL--they're not in the same league.

My reviews at epinions provide more detail if you need it.
Lucerne: http://www.epinions.com/content_218766675588
DTS vs. STS: http://www.epinions.com/content_209422093956

As an STS owner by 2004 , I would go with STS For 05 I would switch to DTS .

i agree