1.) Water-based coatings will indeed raise grain on the surface of wooden models. This degree of this impact will vary somewhat depending upon the species. This feature often makes obtaining a perfectly smooth surface impossible. IMHO, more models are soiled by poor finishing than by shortcomings in other details. (Sealing wood with shellac and then sanding again before applying the water-based coating will go a long way to reducing this annoyance.)
2.) Water-based acrylics can also be more difficult to sand due to their "rubbery" nature when cured. Here again, it may be difficult to get a perfectly smooth finish for this reason.
3.) The pigments in the lower-priced modeling acrylics tend to have coarser pigment grinds that the expensive ones. This results in a coating that is not as opaque as one might wish, and which will require more coats to "cover," which will reduce the crispness of detail required for a compelling scale impression.
4.) For all of the above and other reasons, water-based coatings are frequently more difficult to run through an airbrush.
The water-based technology continues to improve, of course, but this has been the experience of knowledgeable painters since modern water-based coatings started becoming popular. Sadly, the modeling community has not supported sufficient demand to permit manufacturers to continue to produce the excellent "hot" solvent coatings that produced the far superior finish results of oil-based coatings like Floquil. (See:
https://www.paulbudzik.com/tools-techniques/floquil-paint/floquil-paint.html Click on the red book at the bottom of the page for a PDF of the old Floquil instruction book, which contains a wealth of information on how to paint a model well.