Hello! I hope nobody minds me asking advice and opinions but you all seem to know your stuff very well and I would be so appreciative of advice.
My laptop is just for personal use, but I am also studying Computer Science at the moment and I'm finding my 13 inch 2 year old MBA just a bit small and slow to work with, such as when I'm working on scripting and also when I have many screens open working on coursework. So I'd been holding out for the refresh of the 15 inch MBP to do a big laptop upgrade that I've really been looking forward to. I have literally been crossing off the days waiting for the announcement (and then missed it haha lol) because I do REALLY need a new laptop now.
First of all, if you really need something now, buy something now. It's that simple. You can always wait for the next big thing, and it'll always come, eventually. You can save some money with an education rebate and perhaps might also want a refurbished model.
However, I feel a smidge put off with all of the reviews I've read about this being an old Broadwell processor and to wait longer for the Skylake upgrade etc. And I have to admit, I don't really understand why or what the advantage of waiting would be.
Haswell, actually.
People were hoping the new revision would ship with Broadwell; instead, they're still Haswell. That generation is from 2013, though Apple is using revised models from 2014.
The reason they aren't using Broadwell is that appropriate CPUs still aren't out — apparently, Intel either keeps delaying them or has canceled them altogether. Apple uses the 'H' series of CPUs in their 15-inch MacBook Pros, which basically means for cores in a mobile format, and those simply don't exist in the Broadwell generation. Certainly not now; possibly never.
For other variants, Broadwell chips do exist, which is why for instance the Retina MacBook has them. But those would be far too slow for a 15-inch MacBook Pro.
It would've been nice to have Broadwell-H particularly because of GPU performance improvements.
Skylake is the upcoming generation, which may add stuff like Thunderbolt 3. Guesses on when Skylake-H is coming are really all over the map from this fall to late 2016.
but then I always have this mentality that I don't want to be buying new laptops every couple of years, I want to spend wisely so if it's genuinely going to be better to wait then I'd probably make myself wait.
Sure, but you'll always be chasing after the next big thing. When and how often you upgrade should depend entirely on what you can afford.
But for the uses that I listed above, would the new 15 inch MBP be a good investment for me?
It's definitely still a good laptop. The SSD, the amount of RAM, the screen, etc. are all great.
(Personally, I'd love even more RAM. But I'm quite the edge case there.)
The CPU, and consequently the integrated GPU, are getting a little rusty.
And which of the two models looks best? I think I'd rather have the 512GB HD but I don't know if I need all the graphic capabilities of the higher end MBP, but by the time I've added the 512GB HD to the entry level model, it's nearly as expensive as the high end model anyway.
The dedicated GPU is far more powerful than the integrated one, but also draws more power, thus reducing battery life and increasing heat, and is more prone to logic board failure. In theory, the OS intelligently switches between one and the other; in practice, if you can live without dedicated graphics, consider doing so. You mention Final Cut Pro, though, so the additional graphics power may just be worth it.
I just wondered if people thought I might be wasting money or if I would see a significant performance improvement in the speculative Skylake refresh next year.
It'll absolutely ship with a better integrated GPU (its Iris Pro graphics will be two generations more advanced), and will therefore tilt the answer further towards "don't bother with a dedicated GPU". The CPU won't change much, but probably isn't your bottleneck anyway — and even with today's rMBP, you'd benefit from having twice the cores.
But, again, it's about how long you're willing to wait. Maybe you buy it now, and Apple releases a Broadwell or Skylake rMBP in fall. That'd suck. But maybe you wait, and Apple doesn't release one until late 2016.