The "feel and character" will always depend on the source and of course the skill of the modder(s). Most mods "borrow" from other sources, Many of these sources do not fully model the real-world track. While a modded track may have great feel and character, it may not match the feel and character of the actual track. Even modders work under time/budget.
Laser scanning provides "precise physical features of each track’s racing surface. ... a mathematical ‘bump map’ of the track’s camber, cracks, curbs, undulations and patches." If the source of a modded track was laser scanned, then the modder basically duplicates the "character" from the source.
I know many modders borrow source data, but good modders will borrow and improve, or rework heavily, or just straight work from scratch.
A half generation later most modders now have super high res aerial imagery freely available on Google, Bing etc, we have YouTube full of HD videos from people with new HD cameras. We have all sorts of reference sources today, that 10 years ago the average modder just simply didn't have at all.
As for feel and character, I mean in the entire finished piece. I appreciate that surface character and feel will not be exact, but to a certain extent that can be 'made up' and still feel good... only pro sim users probably even care.
But for the other meaning of the words feel and character, I can go drive some modded tracks and feel like it's a real place, at a certain time of year, say a lazy autumn afternoon. There is real 'feeling' to the track.
I drive the AC tracks and they feel dead in comparison. Stuff is in the right place, and the right colour, but they feel souless and unrealistic quite a lot of the time.
Again they are great for pro-sim users, but pretty boring to just drive around for 'fun'... because they feel so dead.
So personally I'm not too concerned about more tracks in AC, I'd mostly prefer to run decent modded tracks because ultimately online racing is just as fun and enjoyable on a laser scanned real track, as it is on a modder made track.
That is at least why I think AC needs to remember the core and keep updating it... not just thinking AC is done and just churn DLC content packs.
If DLC helps finish the core great, but until that is clearly outlined and stated I won't be buying DLC to see the core remain half finished!
Dave