I thought I got over it, but that FF bug is biting me again. I purchased a brand new 60D last month and it's been great and definitely giving me the type of pictures I can be happy with right now.
But the recent 5D Mark II price reduction, along with the fact that I could return my 60D with no restocking for another 3 days (checked with the seller), is REALLY tempting me.
What's holding me back obviously is price. Spending an extra $1000, which is what this would cost if I return the 60D and pick up the 5D body only, is already scraping the limit of my budget comfort.
Frankly, you simply don't have the budget to do full frame right. Not yet, anyway.
But I enjoy shooting people - candids/ portraits, sometimes in low light, so seems like a FF is perfect for me.
You might think that, but to be honest, your 60D can shoot fabulous portraits. In fact, I'd argue that with the sole exception of group portraits where you want to isolate the subjects from the background but still have to use a relatively wide angle (or relatively large distance), your 60D will shoot better portraits than a 5D2. Or, at least, make it easier to achieve the same quality.
Why? Because with your 60D, you have a wider spread of autofocus points in the frame, and they're all cross-type. If shooting portraits is your thing, you're probably looking to nail the focus on a specific area of your subject, or you're setting your depth of field deep enough that it doesn't matter.
In the former case, you're going to want to shoot in servo mode (because you and/or your subject are moving, even if a little) and use the appropriate focus point in the frame to cover the target area of your subject. That's where the better frame coverage of your autofocus points comes in handy, as does the fact that they're all cross-type.
In the latter case, the subject isolation capability of full frame winds up doing you no good anyway.
And it's not like the 60D is lacking in resolution, either, at 18 megapixels. You'll be able to print to 36x24 all day long, even at ISOs as high as 3200 (and even 6400 if you do your part to nail the exposure and are careful in postprocessing).
So what I'd do is keep the 60D and get some really good lenses for it. The Sigma 17-50 f/2.8 OS is a killer lens for these 18 megapixel crop cameras, and costs about $620 (Amazon's price). The only advantage the Canon 17-55 has over it is full time manual focus. The Sigma is reportedly even sharper than the Canon at the center of the frame, even wide open. You can pick one up used on the buy/sell forums here on POTN for about $525.
If you do find yourself at the point where you can really afford to go full frame properly (meaning, you can afford the lenses you'd need to get the maximum advantage from it), you can then rent a body and lens to see if it really is for you. If you really like it, you can sell your crop-specific lenses for what should be a relatively small loss. But by that time, you may have enough experience with your 60D and postprocessing that you find that full frame's siren song no longer tugs on you the way it does currently.
That's the case for me, as it happens. For the longest time, I'd intended to go full frame, but the camera was never really right. Not until the 5D3 came out. But before that happened, the 7D came out. For me, that was a game changer. There is nothing it doesn't do really well, and I've been able to get spectacularly good (in my humble opinion, of course) shots with it. Suddenly, the prospect of moving to full frame is no longer compelling, because my gear is capable of doing whatever I ask of it, as long as I do my part.
Use really good, sharp glass and use a really good postprocessor (such as Lightroom), and there will be very little you won't be able to pull off with your 60D. That includes extraordinarily detailed landscapes, stunning portraits, spectacular action, compelling candids, and amazing macro. The current generation of crop cameras is so good that except for very rare situations, it really isn't the camera that's the limiting factor anymore -- it's the photographer, the lens, or the light.
One last thing: if full frame's image quality advantage really were that great, then everyone here would be singing its praises. And yet, the opinions are very mixed. That should tell you something.
(24Lii, sigma 50A, 135L), and for the other ends of the spectrum, sigmaEX 14mm2.8 and sigmaEX 100-300F4.

