The CX IS great. The DIRAVI steering and Citroen powered brakes confuse everybody at first.
It used to be said that if you test drove one, you would hate it for the first 30 minutes, but after that you would wonder why any car was made any other way and you would never want to drive anything else.
As for the engines, until the Douvrin engines were fitted in 1979, the series 1 cars in 2000, 2200, and 2400 cc petrol engine form had exactly the same engines as the last DS models.
If you can't afford a DS, get a CX. If you can't afford a CX, get a GS/GSA or an XM. Seriously. a V6 XM gives around 90% of the experience of an SM, for around 1/20 th of the price.