Compensation for different roles

They can all be nearly equally lucrative. Best advice is to do what most interests you, because in all of the fields there is a big difference from the high achievers and the middle of the pack, and you're more likely to be a high achiever if you're doing what you like.

Capital markets has more potential to pay a lot early on in your career, and your work efforts can tend to pay off quicker...plus you get your commission check as soon as your deal transacts regardless of it's future success. Development is more back ended and risky - the annual cash comp (Salary + bonus/commission) usually won't compete with someone successful in capital markets, but as you progress in your career you'll start getting pieces of the deal which can pay off big when your deals go well. They won't always go well and it can be a timing thing that you can't control, so some people get lucky and hit big promote checks by time they're 30 while others may not get there til their 40s. Development typically has a higher ceiling - there are probably more capital markets guys consistently making $500k - $1M a year than there are development guys, but there are more development guys having $3 - $10+ million years than there are capital markets guys. Not saying you're guaranteed by any means to ever make that kind of money in development, but capital markets guys tend to top out around that $500k - $1M mark except for select few guys (and gals) that really crush it and/or lead entire regions. On the flip side, there are plenty of development guys that are senior at small development shops that you've never heard of that are doing really good deals and consistently making 7 figure promote checks, and similarly there are lots of developers that leave to start doing their own deals and eventually start making multiple 7 figures and up that you'll never hear about. 

I'd consider to the type of risk you like to take. Both are risky endeavors. Capital markets will eventually be eat what you kill. If you can't sell or build a rolodex, you're screwed. But you aren't quite taking the same type of monetary risk. Developers have to eventually start risking their own skin to make the big money, and even if you're just working for someone else you're likely taking a smaller salary than your peers in exchange for getting pieces of the deals. These are deals that have 3 - 5 year timelines - you can work your ass off for years on your development and have everything going perfect and you go to bed at night starting to think about what you're going to do with your 7 figure promote check next year when the deal stabilizes and sells, and all of a sudden the Fed decides to raise rates by 500 bps in 18 months - all of a sudden that 7 figure check is completely gone and all your efforts the past few years only paid you your below-market salary - even worse if you're the owner of the shop who might not even take a salary and you're expecting probably well into 8 figures for the several projects about to crystalize only for them all to get wiped due to something out of your control. Point is - there's trade offs to it all. You don't get to the 7-8 figure checks without sacrificing something. For investment bankers it's their time/lives/well-being, for developers it's the uncertainty and risk. Figure out what you're going to enjoy the most and be most willing to endure the BS you'll have to go through otherwise you'll probably never make it to the big money anyways.