We recently stayed at the Gibson for a few nights - and I must say we were most impressed.
The hotel is amazing - really modern and sort of 'funky'. It was not what I was expecting. It is very different - for starters the reception is on 3rd floor - as are bedrooms and restaurant/bar. Our room was a little on the small side but it had everything we could want. It was really clean and comfortable. Bed was super comfy. We requested a bath as I believe only some rooms have baths. We had a balcony with nice views - it would be quite nice at a warmer time of year. They have really cool art work all over the hotel (and in the rooms). It is not a 'Four Seasons' type of 'luxury', 'romance', 'staff falling over you to help' hotel - if you feel that is important for your stay.
Wifi is complimentary - however you need to get little slips of paper at reception (separate one for each phone or device) - I think they last 24 hours. Several of mine didnt work which was a bit frustrating at the time. Breakfast was great - good variety of hot and cold items. Day 1 (Friday) was terrific - lots of everything - however day 2 (Saturday) quite a few items had run out at 9.30am and weren't replaced by the time we finished. Not the end of world - as the overall variet is good.
We also ate in Hemidemisemiquaver (I think thats how they spell it) - - which is the bar dining area. They have a terrific Asian restaurant here. Food was fabulous - really authentic, service was prompt even though the place was jammed full of concert goers (02 is literally outside the front door). Prices were very reasonable.
To clarify various postings here about the car park - the price is €14 for 24 hours (not for your entire stay as one poster said). Get a multi entry card at the car park reception (separate company from the hotel - so Gibson reception cannot help you) - and you can come and go as you please. We pre paid - which was very handy.
Luas red line stops outside the door - which we found very convenient for getting into the city centre.
To sum up - a very modern hotel with fabulous facilities. 02 and Luas couldn't be nearer. Shop around for best rates with price comparison websites. Factor in - breakfast (€15) and parking (€14 per night). I would highly recommend it.