Queens University vs Ulster University - Computer Science Watch
More about Queen's University Belfast
1) Ulster is a better place to be for doing undergrad in CS: UU generally work with students a lot more at undergrad level and student satisfaction surveys always have Ulster a good bit ahead of QUB. This is my experience too. QUB generally don't care if you are having a hard time or are struggling or need extra support. QUB is a research based uni (more on that later) so a lot of their staff and teaching resources tend to go towards research. Taught courses, including CS, QUB tend to leave students to their own devices. Plus the overall education you get at both unis at undergrad is the same.
At Ulster, if you are having problems or need extra support, I've found teaching and admin staff will really do their best to help you.
2) QUB is better for a PhD in CS: As noted above, as it's part of the Russell Group QUB tends to have a fixation over research. A lot of their academic staff tend to spend a lot of time researching. In fact one lecturer at QUB told me they'd rather not be teaching students if they could avoid it, they love researching. It's not an uncommon attitude in QUB academic staff (at least in CS). While this sucks if you are undergrad, it's great if you're a PhD student. QUB will provide you with a lot of opportunities and you will make a lot of great contacts through QUB if you do a PhD in CS there. With Ulster it doesn't seem as if there is the same connections with industry as there is with QUB.
3) The Russell group fallacy: Ah the Russell Group. The Holy Grail of academic achievement in the UK...except it isn't. Just as an example, there is not a single major tech company in Belfast that only employs QUB undergrads. They all take UU grads too. The idea that QUB is "better" as it's part of the RG is nonsense. Industry here doesn't give a hoot about that. Someone with an ambivalent attitude to CS who scraps a 2:2 in CS from QUB is always going to lose out to an enthusiastic CS geek with a 1st in CS from Ulster. You can switch the unis round in the last statement and it still holds true. The point is the uni you go to for CS in NI really makes no difference to your prospects after uni. None.
On another note, if you are still fixated on RG unis consider this: I applied to RG unis for masters after undergrad at UU (QUB,Glasgow, Edinburgh, Warwick, Birmingham). I got unconditional offers from them all. Literally only went to QUB as it was the cheapest lol! Which brings me to....
4) Price: QUB have made no secret about the planned hike in fees that are coming up at undergrad. Ulster has yet to match this rise in fees, but no doubt they will at some point. That said at present you are getting an equally good education (IMO) at Ulster as you are at QUB for a lot less money. That's another plus point for UU over QUB at undergrad level.
In conclusion, if you want to be well supported, have a more enjoyable learning experience, a good education, and save money at undergrad level, do CS at UU.
If you aspire to do a PhD in CS, I'd recommend QUB.
Hope this helps. If you have any questions let me know. And sorry this came too late for the original poster.