There were two versions of the CTS-V1, the 5.7-liter LS6 and the 6.0-liter LS2. The initial version was a rival for smaller cars like the Audi S4 V8, the BMW 330i Performance Package (there was no M3 sedan at the time), and the Mercedes-AMG C32, but the final version eventually turned it into a rival for bigger cars like the Audi S6 V10, BMW M5 V10, and Mercedes-AMG E55 Kompressor.
Notice that I said "rival", not competitor. The Series 1 CTS-V had no true competitors - unless you count the Chrysler 300C and 300 SRT8 models, or maybe the Lincoln LS V8 Sport, and even those had much different approaches to a performance package.
2004 Cadillac CTS-V LS6
Claimed Power: 400 hp @ 6000 rpm
Claimed Torque: 395 lb-ft @ 4800 rpm
Bore x Stroke: 99 mm x 92 mm
Number of Cylinders: 8
Boost Pressure: naturally aspirated
BMEP d: 11.0 bar
VE un-boost: 100.00%
VE boost: 100.00%
MPS @ Peak Power: 18 m/s
Actual Power: 409 hp @ 5870 rpm
Actual Torque: 399 lb-ft @ 4400 rpm
Drivetrain: RWD; 6MT
Estimated Weight: 3887 lb
0-60 MPH: 4.8 sec
0-100 MPH: 11.3 sec
0-150 MPH: 34.5 sec
1/4-Mile (street): 13.3 sec @ 109 mph
1/4-Mile (drag): 12.9 sec @ 108 mph
Top Speed: 168 mph
Motor Trend Figure-8: 24.7 sec @ 0.84 G
Nürburgring Nordschleife: 8:31
Top Gear Test Track (Power Lap): 1:27
2006 Cadillac CTS-V LS1
Claimed Power: 400 hp @ 6000 rpm
Claimed Torque: 395 lb-ft @ 4400 rpm
Bore x Stroke: 101.6 mm x 92 mm
Number of Cylinders: 8
Boost Pressure: naturally aspirated
BMEP d: 11.0 bar
VE un-boost: 100.00%
VE boost: 100.00%
MPS @ Peak Power: 18 m/s
Actual Power: 431 hp @ 5870 rpm
Actual Torque: 420 lb-ft @ 4400 rpm
Drivetrain: RWD; 6MT
Estimated Weight: 3793 lb
0-60 MPH: 4.5 sec
0-100 MPH: 10.5 sec
0-150 MPH: 31.0 sec
1/4-Mile (street): 13.0 sec @ 112 mph
1/4-Mile (drag): 12.6 sec @ 111 mph
Top Speed: 183 mph
Motor Trend Figure-8: 24.9 sec @ 0.87 G
Nürburgring Nordschleife: 8:28
Top Gear Test Track (Power Lap): 1:26
https://docs.google.com/spreadsheets/d/11T6iUr6uQ_TkqqFB1nPvV0malo9X5HgXlK3JZ2du1RA/edit?usp=sharing