[X 2014 Q&A, Help & Troubleshooting] Lunatiic:
So, I used both on a local retail store (The X Play being a bit more expensive) and here are my conclusions (I bought the X2014 a week ago):

1) The Snapdragon 801 + Adreno 330 performs considerably better than the Snapdragon 615 + Adreno 405.

While using the phone for regular stuff, like web browsing, whatsapp, instagram, etc. there were micro lags on the X Play that were almost non-existent on the X 2014. I tried to push both the hardest I could and the X Play had much more hiccups (Like fast scrolling facebook, fast pinching to zoom on chrome, quick switching between tabs on snapchat, quickly switching between apps), I guess it's due to the lower clocked A53 cluster being active more often to preserve battery. Nonetheless, both performed very well considering the price tag.

When benchmarking, the X 2014 Won on both graphics and cpu. My X 2014 always goes from 2900-3100 on Geekbench 3, while the X Play started at 2500 and went all the way down to 1700 (I guess it's due to overheating). Antutu it's the same, the X 2014 sticks between 47K and 49K, while the X Play went from 36K to 27K (Again, I think it's overheating). Bear in mind that I re-did each benchmark 5 times and I live in a hot country, which regularly sticks between 30ºC.

While gaming, same thing happens. I'm a heavy Clash of Clans, Candy Crush and Asphalt 8 player. On Clash of Clans there were no difference at all, both performed admirably and there were no hiccups at all. Candy Crush both lagged a bit on the pop-ups and when sync. with facebook, but during the gameplay I saw no hiccups on both. But when playing Asphalt, after like 30mins I saw the play getting a frame drop, but nothing that made the game unplayable, just a bit less smooth.

On the heat side, the X 2014 got warm after 30Min on Asphalt 8 while the Play was a bit hotter, but nothing that you can't lay your hands on. Acceptable.

2) The battery is where the X Play wins. I couldn't test it much becase I was on the retail store, but seeing their XDA Topics, the X Play can achieve easily 2 days of battery, even with the overheat issues. My X 2014 does around 5 hours SOT when on good coverage and WiFi (24Hrs off the charger), and gets maximum 4Hrs SOT (usually 3h30) when on 4G with mixed coverage (24Hrs off the charger). My X 2014 came with the Turbo Charger, so I can quickly replenish battery any time I need, and due to the smaller battery, Power Banks are more efficient (I have the Mi Power Bank 10400mAh and I can charge the X 2014 around 3,5 times until it gives up, the X Play I suppose that it would charge less than 2 times).

But still, X Play is the clear winner.

3) Build quality depends of who is holding these phones. I particulary found the X 2014 way prettier than the X Play, and the overall build quality also better (loose buttons on the X Play are a bit annoying). The X Play is a tad bit heavier and bulkier, the X 2014 feels a bit more polished and premium. The front fiering speaker is mono on both phones, and I found them to be quite similar. The X 2014 wins, for me.

4) Camera on the X Play is considerably better. Don't get me wrong, I'm more than happy with my X 2014 camera. When on good light conditions I can take pretty damn good shots, but I mostly use the camera for Snapchat, Instagram, Whatsapp, and for college, so I don't need the best of the best camera around. The X 2014, with the SD801, is capable of 1080@60 and 4K while the X Play only records up to 1080@30. Recording on 1080p 60fps is not supported on the stock camera app but it's possible. The main downside of the X 2014 camera, I could see, is when trying to get macro shots.. the camera struggles a lot when trying to focus on near objects. I don't have 4K screens to use the X 2014 feature, so for me, the X Play wins.

The 5MP Front Camera on the X Play also outperforms the 2MP on the X 2014.

5) The screen also depends on your taste. I found the 5.5" a bit big for my taste, 5.2" being exactly what I needed for one handed use. The X 2014 has much deeper colors, more contrast but the screen temperature is a bit high, the whites look yellowish, but I got used to it. The X Play has a bit more washed out colors, due to the LCD panel, but it's more color accurate. So, it depends on the taste. My main fear when buying the X 2014 was the infamous screen burn-in, but my display is fine until now. No winner here, it depends on your taste.

6) One downside of the X 2014 is the lack of microsd expansion. For me, 32GB is more than enough.. I still have 18GB free out of 25GB, with all my music, photos, backups, documents, apps, games... But having a microsd is great for emergencies and stuff, so the X Play wins for storage options.

In the end it's up to you.. I went with the X 2014, but the X Play is also a nice phone. Also, bear in mind that the X Play should get the next version of Android ( after Marshmallow ), while the X 2014 should stay at 6.X Marshmallow if Motorola keeps their updating cycle time.

Cheers and good luck with your next phone!