I like the SPT intake. My in-laws got that for me for Christmas and my wife got me the heatshield, so haven't had it on that long. I am corny and like supporting the genuine subaru parts, I already have the SPT catback. It adds a great sound, which I am a sucker for. Subaru will say though that with the SPT catback, heatshield, and intake will give you an increase in horsepower. Not huge gains, but they do market those three items as a "power pack"
As others have stated, the intake for a subaru is not really worth it until you are putting down a lot of horsepower. Its not ideal for mod to be done early on, even though I did it. A big thing if you go through with it is watch out for the Short Rams that differ in design from the stock one. Examples that are fine, Cobb's short ram and the SPT. To my knowledge all the other ones differ in design and mess with the Mass Air Flow sensor, thus why you need to have a tune because you will throw a code. So you can get another one, but get a tune, or buy the ones I said above and you won't have that problem.
Good luck, and remember this is your car so make your own decisions about it. It's good to find out and research but don't some strangers dictate how your car should be.