These older models of the Titans 1sts are very good and extremely reliable.
I still would see that I could change the filter rings for the newer ones, because simply the area which can absorb possible dirt from the tank is bigger.
I think that's the reason AL changed the design.
The flat filter design is anyway not so perfect, because it has a smaller filter area than for example the usual conus design.
And concerning worries about the orifices, you know that if you don't need it extremely fast, you can get from me any parts from SP, AL, Apeks, Cressi, Sherwood, DiveRite and XS Scuba.
Just in case......