I have driven all those engines.
1. Stratus rental car with an I4 while my Cutlass was at the dealer.
2. Multiple Sebring convertibles with the 2.7, including the one which died on me on the Florida Turnpike while at a 75mph cruise.... the car had about 3,000 miles on it, I picked it up with 2100 miles on it.
3. A 300 with a 2.7.
4. A 300 with a 3.5.
5. A company Jeep with the 4.0 began leaking around 12,000 miles.
6. Observations of the neighbor's Jeep which leaks oil all over the pavement in front of my house. It's a 98ish Wrangler with the 4.0, but I can't remember it not leaking.
The Stratus was a fairly beat to hell rental. I'm perfectly willing to admit that perhaps I didn't give it a fair shake, but there has yet to be a Chrysler I4 that has changed my mind.
My opinions of the 2.7 are based on just the Sebring Convertible and the 300. I don't know what it would be like in a lighter car, but both of those are just too much car for that engine. Sure it puts out respectible numbers for it's size, but it is just not enough engine for those cars.
The 3.5 I found to be nothing great. I picked up this rental with 250 miles on the clock. It's got the punch and the power, but it seemed to be on par with a S/C 3800 in terms of refinement. I'm not a 3800 hater, but I do believe it has served it's company well and now needs to retire. Two co-workers blew the 3.5s in their Intrepids in 2005.
I have no problems with the performance of the 4.0. It does an ok job at what it's ment to do. It's not a sports car engine, and don't I expect it to perform like one. What I have a problem with is the big oil stains in front of my house that make it look like the Valdez crashed on my curb.
Frankly, I'd love to be a Chrysler fan. I love the looks of the 300C from the outside. I hate the ergonomics of the inside. The cruise control location alone gives me pause at the rental car place.
I'd love to love the Sebring convertible. Few days go by where I don't miss my Cutlass Convertible 2+2. The 3.4 DOHC had punch. Chirping the tires in 2nd was very easy. It was a big, comfortable, convertible with balls. The Sebring isn't as roomy, doesn't have as much trunk space, doesn't have as much engine, and has about the same quality interior..... yet the Cutlass came out in 1991. When Chrysler can meet/beat a 1994 Oldsmobile convertible in terms of performance, interior space, trunk space, and interior design... GM will lose a customer, because I'll be trading my CTS in on that.
So yeah... no speculation here.