The older style Teg I assume (98 - 2000)? Not a bad change, but not a step up really either.
Tegs are good cars, and feel more planted than the Cup, due to how low they (and you) sit, also lots of fun using VTEC.
The downsides are they look very dated, and werent great lookers to start with, and dont have many of the little extras you have in the Cup. They are also quite a bit more raw, but not so much so that it makes them a mission to drive.
They do have a LSD, which is superb, and ABS, plus the braking system is excellent, though in the dry id put the Cups ahead.
As far as performance goes, I have two mates who own them, and have have had a few blats about with them. Theres really nothing in it, the Teg does give that more planted feel, which makes the driver a little braver through cornering, but ultimately, both being well driven, the Teg wouldnt (and doesnt) make any ground on a Cup.
If youre after a good performance coupe, thats a lot of fun, then its quite a bargain, just dont expect to be blown away with it going from a Cup.
