I love my HP-CS, and always recommend them, I can't comment on the Patriot as I've never used one. But I would say think about what you are hoping to achieve - and then decide - can you do that with the Patriot? I'm guessing you chose it because you thought it might suit your needs, has that opinion changed? Are you getting on well with it? Is it comfortable? Are you seeing an improvement in what you are doing, and are you starting to get to grips with all the different techniques you need to learn to begin to reach your goal. Can you see that continuing, and as you get better will the brush continue to allow you to refine what you are doing even more. Are you not getting the results you were hoping for? Taking into account your relative inexperience - do you think the airbrush is holding you back? Before you joined the forum and read about the eclipse, were you happy with the patriot, or were you having doubts about it, and reading about the eclipse has made you wonder even more?
If you are getting on well with it, and with the option of the conversion kit later on, then maybe you don't need to change. Ideally it would be good if you knew someone who would let you try their HP-CS, or have a shop that would let you have a demo so you could compare. If the answer to the above is, that you feel you aren't getting what you want from the brush, or feel it's holding you back, then it may be worth considering the Iwata. IMO it's an awesome brush.
I think your painter friend is right in many ways, it's the hand holding the brush that creates the art, and once you've got to grips with learning to airbrush, refined your trigger control, built that muscle memory and feel comfortable with the different techniques, an experienced AB'er can get great work, with fine detail from any quality brush regardless of nozzle size. But it is also true that people learn better, and feel more comfortable with some brushes rather than others. I used a DAGR before the eclipse, but ended up sending it back due to some issues, and decided I would try something different next time. After lots of research to see what would suit my needs best I chose the eclipse, and suddenly things I was struggling with before just seemed a whole lot easier, and I never looked back. Without having the two brushes side by side to directly compare it's hard to say what would suit you more, but if you are not wanting to spend more money and you are getting on fine with what you have, then you could just stick with the Patriot. You still have the option of trying something different later on if needed, or with more time and experience under your belt, if you feel you are outgrowing it, you could change then. You are already a step ahead of the game from those of us who started out with practically unusable cheap knock offs
If you are already feeling unsure about the Patriot , then maybe not having confidence in it could hold you back, or leave you wondering whether it is the brush or the painter that is to blame. in that case the Iwata could be just what you need.
Only you can answer these questions. For me not having the ability to remove the needle cap is just a big no no, but every ones preferences are different. I guess it comes down to how things are going with what you have, and do you think having something else will improve that.