As was said above, sure, you'll stop quicker, and you can paint the calipers up for show (seems like that's the road you're taking with your list of mods in your signature anyways), but you'll gain weight and unless you've got the know-how, time, and patience to do it yourself, you'll most likely end up paying out the anus for labor at a garage.

 

Stopping distance is shortened by something like 5 feet in a 60-0 test. Not enough to warrant a swap. Looks nicer, I suppose. Easier maintenance definitely. Better aftermarket options for pads as well.

Got a '95? 4 lugger? You'll have to swap front and rear out to a 5-lug setup, which means new wheels. There were never 4-lug rear discs on the Neon.

Master cylinder swap - not required.
Brake lines swap - not required.
Brake controller - WTF? not required.
Proportioning valve can be kept as well, in case that pops up.

For the rear, you will need the spindles (with hubs), caliper assembly, rotor (duh), and e-brake cables.
For the front, you will need the spindle/hub, caliper assembly, and rotor.

 

Proportioning valve is different.
Brian

 

The 1st gen primary and secondary metering valves (proportioning valves) have the same part numbers, regardless of year and/or rear drum vs. brake. The brake boosters are different between ABS and non-ABS. All non-ABS neons use the same master cylinder, regardless of rear brake configuration. With ABS, there are different part numbers for disc and drum. I have the parts catalog open in a different window in case you're wondering where I'm getting this info...

The swap has been done successfully dozens of times without swapping proportioning valves, master cylinders, etc. For those with ABS, the same ABS controller and modulator valve were used in all aplications, and do not need to be changed out.

For the rear, you will need the spindles (with hubs), caliper assembly, rotor and e-brake cables.
For the front, you will need the spindle/hub, caliper assembly and rotor.