I can only go on my own experience but i had a uwatec for a SHORT time and switched to suunto, batteries and buttons seem to be problematic on uwatecs.
been using my vyper for 3 years and its done 100 + dives still got full battery and all the buttons etc are working fine - i now have a D9 (yeah - i know its the 'fashion' one!) and although you have to get used to the smaller screen and layout its a great computer, easy to use etc.
so if it was my money i'd go for the D6 - or hand till you have an extra few quid and get a D9, some good deals around.
dive safe