I had a 2012 SRT8 300 so perhaps I could shed some light as that is another car you're looking for.
The 300 is a very quiet, very nice comfortable car. The infotainment center is better. It has all of the bells and bluetooth junk a 2012+ car has now days (even mid level). The sound system sounds better. The surround sound with DVD's is pretty good. The touch screen stuff is nice, easy to use and looks better. The SRT digital gauges are pretty, work well, give you AIT, engine-oil temps lots of other nice things. The Hemi sounds better when you open it up. The torque feels like it comes on a little earlier, and in a smooth flat way. The torque makes the car drive very smooth with the 5 speed. Its never hunting for a gear. It has all the power you need with the 392. The charger is a bit sportier looking on the outside, but the interior on the 300 is 10x better. The seats are very comfortable, perhaps a bit softer than Racarro. Its a great blend of muscle car, luxury, fun for an everyday car. They are also quite fast.
The V is a different animal. The V is a smaller performance sedan with features designed to make it perform while driving fast on a track and on the street. The SRT8 is a large, less agile sedan, that has features added to it to make it perform better on the street, and be adequate on a track for some weekend fun. The V had systems designed and engineer specific for it to create a Euro-busting icon in the automotive industry which it did. The SRT8 is a great looking car, with a great performing engine, that grabbed some features/technology off other cars, to fine tune the beast into an all-around better car - which it was very successful at doing. The SRT8 is a car designed around a non-performance vehicle, while the V is designed after a more sporty sedan to begin with.
I feel like every inch of the CTS body was thought out. When it rains I can see the water moving over the panels with the water droplets as they leave a trail. I don’t know how aerodynamic the car really is. I would suspect some of the angles and edges may hinder this some, but the car just looks thought out. Being a polarizing car in the looks department, many probably think the opposite.
Ultimately for me, it just came down to my dream car, which is the V. The V isn’t really better, faster, more refined as a fun day to day bad ass sedan, but it’s just better at going fast. The V has a mystique going for it that the SRT8 doesn’t have. When you take a corner fast in the V and accelerate through it, you feel like you’re planted and driving a $100,000 supercar. The wheels stay down. The rear isn’t clunky. The car doesn’t feel heavy. The magnetic ride control eats up the terrain. The steering is easily the best out of any car I have driven. The power comes smooth, and presses you into the seat. The V launches better, and does a better job of continuing to put down the power to the ground. The SRT8 isn’t as stable, and does not integrate its power into the driving experience as efficiently. The SRT8 feels like a heavy car that’s been tamed a bit. The V doesn’t feel like a heavy car from start to finish, over bumps, through corners etc. Even though I rarely use it, that extra race pedigree gives me a contentment that the SRT8 didn’t satisfy. In truth, the SRT8 is a better car for the money, and it wasn’t an easy decision.
I don’t get the obsession with Bluetooth streaming. Its sound like crap, it cuts in and out occasionally. It’s convenient, but sometimes syncs when you don’t want it to. XM radio sounds like garbage in general -hollow, no power. The SRT8 has the worst reception I have ever dealt with. The V’s satellite radio is much better, but I still find it akin to streaming radio over the internet back in 1998 in terms of sound quality. The on board hard drive, now having had it with the V is better for me personally. It allows you do download mp3 at maximum quality (still not CD quality mind you) right off a memory stick.
Gripes about the V:
It lacks some tech features like tilting mirrors, functioning blind spot monitoring, active headlamps, adaptive cruise control.
The interior is really, really nice, but I would have utilized REAL carbon fiber in place of the piano black. The piano black looks fantastic but is the ONLY noticeable cheap part of the interior, and this fact alone makes it stand out.
Larger Paddle shifters should be standard, not an aftermarket necessity.
The clock looks like a cheap $15 Walmart special. Fix this with an Aeroforce Gauge. Why even have it in there if but to execute it so poorly?
The liquid crystal display of the climate control temp is WAY too large and bright. Stupid.
Ambient lighting could be a little brighter and in a color.
Cadillac exterior paint is inconsistent.
Rear bumper needs a true diffuser design.
Headlamp light bar DRL should be brighter.
I feel like the air intake system could have been better design, but I guess judging by performance it obviously works adequately.
MPG could be a grip, but I’ve driven two SRT8’s, a corvette and a trans am previous to this V so I’m basically used to getting 15MPG. I’ve been living with the “smiles per mile” mentality for a lot of years.
Headroom in the coupe is a bit constrained but I understand the compromise made to get the swept exterior look. I can live with it!
Stereo needs more EQ settings, separated sub levels etc.
The car in general sits a little high stock for my taste. I’m sure there is a reason for it. Aesthetically, I just think the wheels and rubber could fill out the wheel well, and the car could hug the ground better.
In terms of what I miss about the SRT8, really nothing. I might miss the heater steering wheel in the winter. I miss the sound of the hemi occasionally. There really is no sacrifice with the V other than money as its not a cheap car.