Iwata Neo or new airbrush?



Okay, so I purchased an iwata Neo a few days ago, and I've been using it, but I'm having a couple issues with it. For starters, it seems to clog up on the tip very often and second, it just doesn't seem to want to paint in fine lines, so my question is whether you think getting a better airbrush will help or whether I'll just have to learn to continuously wipe the tip and not be able to paint really fine lines (I'm using it to airbrush models)? I seem to be able to paint fine lines, but they're very very light and it doesn't last long before I have to clean the tip. I'd be willing to go up to more like a $100 airbrush if it would help. Any help would be great! Oh, and I'm using the harbor freight compressor at around 15psi.
$100 wouldn't bring you too much further or better than what yo have now, you didn't mention the paint your using, but generally all brushes will clog and it almost certain that it's the clogging that is stopping you getting fine lines, you need to take apart and clean it thoroughly inside the nozzle, nozzle cap and needle, in order to get fine lines you normally need to get in close and your paint needs to be thinned ad this will obviously affect coverage so your lines would indeed be faint, it's a case of going over them again or enough times to get to coverage/opacity that you want, so there is nothing wrong with your brush, you just need to learn more about it and how it all works.

The problems you have now, you would have with any brush at all and those problems would be even worse if you chose a brush with a smaller nozzle size, there is no harm in getting a newer better brush but you must understand the importance of regular maintenance and precise cleaning, not to mention correct choice of paints, since you mention models I would assume your using model paints such Vellejo, revel or Tamiya paints none of which are designed for fine detail, it's also important to know that with any paints, you can thin the paint but you can't thin the pigment, so heavily pigmented paints will clog your brush no matter how much you thin them and no matter what brush.
I had issues with my neo to. And I guess it's a hit or miss on that one. Some get a good one works like a charm. Some like me it has flaws that hurt. But also what kind of paint. I was using straight createx diluting it 50% but once I grabbed wicked paint I realised it went thru small needles better. If you do decide to get a new brush do this.

Download hobby lobby app each week they have a 40% off coupon but read it cause it limits what you can't use it on. I got my neo and my hp-CS with it. The hp-CS comes in kit only. Costs 125 with the coupon. I'm really loving this gun you will to.

Sorry missed the painting models bit. The paint I said is for illistration. But can someone answer this.

Would wicked air colors work on models since they are designed for automotive?
I gues you'd have a neo with a 0.35 nozzle. 0.35 is a nozzle between detail and large leaning towards large. As such it''s not suited, or meant for that matter for realy fine lines. A very experienced airbrusher will get fine lines out of it but it's not the tool for the job.

As it has one of the larger nozzle sizes you realy shouldn't have that much problems with tipdry, this probably is down to the paint you use or the pressure you paint with. 15 psi is realy low for that nozzle size which will requier some pressure to get the paint out I'd cranck it up to 25-30 maybe even a bit higher.

As indicated by @Madbrush at $100,- you probably already have one of the better tools avaliable for that money. To get realy fine lines you'd probably want to use a smaller nozzle size and the "good" airbrushed than quickly go to the $250 - 450 range. Also keep in mind fine lines are not down to your gun (that only makes it easier or harder) but just down to sheer practice.
Thanks for all the answers everyone! And to answer the questions about paint, I'm using Model Air paint.
I don't think model paint is made to go extremely fine. And like @haasje dutchairbrush said, the Neo it is not meant to go very fine either. But it also depends on what you think is a fine line. If you paint a big poster the Neo is more than capable to do the lines required but will struggle with A4 or letter size paintings. But with experience and good paint and knowledge about paint viscosity and air pressure, you will get the hang of it.
HP-CS is currently going for around $90 on Amazon. As others have said, it's not a dedicated fine line tool, but I have one and it can do fine lines. Just takes very precise finger control, as it'll go from fine to not within only a little trigger travel. It's very reliable and an absolute breeze to maintain, so I don't think it'd be a bad call upgrading from a Neo.

Badger SOTAR also goes for under $100 on Amazon currently (in fact as of this writing it's ten bucks cheaper than the CS). It is a dedicated fine line brush, and so is easier to control in that context than the CS (better atomization too), but on the flipside it is also much fussier to maintain.
A few years ago I did a comparison between a Micron (in red) and an Eclipse (in grey). I consider the Micron to be fine and not the Eclipse. This is in inches.