Might want to investigate more about after sales support. In my experience if something in your diving kit is going to fail or have issues over time it will mostly likely be you dive computer. Especially when you start to get fancy ones like these that have all kind of features.
I love Apeks regs and swear by them and will probably dive them for the rest of my life but... Apeks is not the best company for support. And I highly doubt you will get any support for a faulty button, failed depth sensor, screen LED's going out, etc. (When Apeks first came out with there dive mask I picked up 2 of them in the UK, dove them for about 6 month and both straps ripped out of the frame, emailed Apeks multiple times and got nothing back from them, called them and they said I need to go through the shop I bought them from they can not help me. It was useless just ended up throwing them away)
Yeah GPS is kind of cool for your dive log but I would not make this a major buying points. And the analyzer well it only does o2, and personally I hate those kind that you have to crack open the tank just perfect and bleed off 10bar just too analyze. If your truly are doing diving where you need your own analyzer then you would be buying a Divesoft. So I would not make the Apeks o2 analyzer one of your main buying points either.
Personally I would be looking at Shearwater simply because of there long rock solid proven history of providing one of the most used and trusted multi gas decompression dive computers on the market and there rock solid customer support. (I think alot of people forget that be for the Teric and Perdix AI made Shearwater a "popular" dive computer Shearwater and maybe Liquivision were "the" dive computers to have in the technical diving community an they have been perfecting computers for almost 20 years now. Shearwaer has been in the computer business way be for the Teric and Perdix AI so they kind of know what they are doing)
Not saying there is anything wrong with the DSX but this is Apeks first attempt at anything electronic, something to think about... Check the forms and you will read countless post about the amazing customer service from Shearwater. Personally I have had 1 Perdix 2 Petrel's and 1 HUD replaced by shearwater no questions ask and all were waaaaay out of warranty date. Also many of my friends have had HUD's replaced by them no question asked even when it was clearly the user that cracked it letting it dangle around and hit stuff. Also Shearwater is really good for worldwide customer service. 1 of my computers was replaced in the UK posted back to Germany, 1 in New Zealand posted back to Indonesia, 1 in the US, and my HUD then sent to Hong Kong for a friend to bring me.