Oil vs Acrylic

It's about preference,I like enamels like Modelmaster, they cover great and there is a great color range but they are smelly,I use acrylics like Tamiya,but range is limited,I like Vallejo's range,but they could be finicky in airbrushing,so it's a combination of many factors to consider.

I assume from your explanation you mean enamels as opposed to artist type oil paints.

Over the years I've seen the trend go towards acrylics.

Several reasons.

Acrylics are easier to clean from a regular brush and airbrush.

Enamels and their cleaners/thinners have an odor that many people do not like.

Acrylics come in a larger variety of colors.

Acrylics are more available. Especially if you include craft paints.

Acrylics tend to dry "flat". Desirable to almost everyone except maybe car modelers.

Acrylics are easier to remove from a model if you need a "do over".

In my own experience acrylics have a longer shelf life and are more likely to be successfully "reconstituted" if a jar does go bad.

Its also been my experience that acrylics are more forgiving when diluting for an airbrush.

On the other hand

Enamels tend to cover better, especially hand brushing.

Enamels are more resistant to handling and scratches.

I'm an enamel user.  It works fine for both hand brushing and airbrushing. I do not like the very rapid drying of acrylics for airbrushing.  You must never get distracted and put off cleaning airbrush IMMEDIATELY after finishing, or it will be very hard to clean up airbrush.  Folks have recommended I always add retarder, but I do not have to do that with enamel.

I do a fair number of models that need gloss finishes, and I find I can get a better gloss with enamels than with acrylics.

I know some people say acrylics are oderless, but I thin with isopropyl, and I can sure smell that stuff.

Like Don, I'm basically an enamel person - for most of the reasons he has given, but also because they seem to last longer in storage than any acrylics I've tried.  I still have usable bottles of enamel paints from the 70s, 80s and 90s.  Having said all that, I do find that acrylics work very well as base coats on figures. An oil topcoat will often lift an enamel basecoat no matter how long it has dried.

The ONE thing I do not like about Testors enamels is that once opened, the shelf life is limited.  Unopened they do last a long time, but once you open a bottle I find about six weeks or so and it starts to go bad.