Pluspunten
You get to learn a bit about a large, tightly-controlled server farm environment (if you're into technology). As a trader I would say the best thing is that they have lots of data to analyze and exchanges to trade. But on the other hand, they make every effort to try to get you to use their IT staff to "help you" code your strategy, which means you are leaking ideas to them (see below).
Minpunten
The main issue is with their business model:
1. It is ironic that they are called "Sun Trading" because they are Intellectual property vampires, sucking your trading ideas out of you and copying them for themselves. Their codebase is littered with other traders' ideas. Where are those traders now? Fired.
2. I have seen the same thing happen with technologists. They take any and all suggestions you might have (well of course they do!) and give out zero credit. Keep your best ideas to yourself. Don't give them those ideas thinking it will get you that big bonus or prevent you from being let go. You have been warned.
Their entire business model revolves around this theme. They have bought entire trading desks just to bring in the IP, and then whatever happened to those people? Gone. Look it up, this is all verifiable fact. They even did it with some upper management (no names, but google who their previous CEO was).