My son and I both have Puck Pro+ computers, and have done over 100 dives on them. They are a perfectly fine computer for recreational diving. One button is very simple, but can be a bit of a pain sometimes. However, they work well and I haven't felt the need to replace them yet, since they do work fine, handle nitrox fine, work fine at depth (115ft is our deepest so far), etc. When I bought them I seem to recall reading that they were less conservative than Suunto. The Puck Pro+ does allow you to set it to different conservative settings, and we moved ours to the least conservative after diving with others who had less conservative computers. But after that no problem -- we are often the last ones up on boats, and even then almost never from NDL limits.
For a while I thought about upgrading to a Mares Smart, but recently some friends have gotten them and the display is not as big as the Puck, so I'm not thinking that any longer. Now I think that when I do eventually get a new computer I will go with one like the Aqualung i330r or the Shearwater Peregrine -- mainly because I like the fact that their displays can be read on night dives without needing to press a button or shine the light on the computer. But all in all this is not a big thing, and both of those are 2 or almost 3 times what you can buy the Puck Pro+ for if you find a good sale.