Excerpt from the review :
Opus #1s vs Cayin N5ii - We should start with the obvious, Cayin N5ii has a lot more features than #1s, coming with Streaming abilities and a lot more usage potential, for those who are into this type of thing. Cayin N5ii also comes with two microSD slots, so it does make a pretty interesting device, being really well-priced and very very attractive. In side, N5ii is smaller than #1s by a good margin in every direction, but since we use Mi Max 2 as a smartphone, we usually prefer larger displays for easier control. Cayin N5ii had a few bugs to sort out at first, but now it is getting stable, while #1s has been absolutely stable since the first moment we received it. The display, on the other hand, has much better color, much better contrast, much better brightness, larger size and looks better on Opus #1s, while it is smaller on Cayin N5ii. The overall navigation, on the other hand, is more natural and feels more native on N5ii, where with Opus #1s, we got used to it, but it isn't always the most intuitive navigation. Cayin N5ii can sideload apps and has Hiby support, while #1s does not have any of those features. The sound is more neutral on Cayin N5ii, with a slightly colder and more aggressive approach, thing which we actually like a lot, as it also feels a tad more revealing. The soundstage is similar in size, and there is a similar amount of overall detail, although on N5ii it is more expressed. In the end the two devices are very different, N5ii being a multi-purpose device with a much wider usage scenario, covering even #1s's main usage scenario as it features two microSD slots, but it is a smaller device, more nimble, easier to use with one hand for people with smaller hands, Opus #1s having the better display, and more driving power available to it, along with a warmer sound and a more laid-back presentation with a slightly more effortless and less aggressive presentation. They serve very different usage scenarios, and we feel that users will be more attracted to one of them, depending on their usage scenarios and tastes, the device design being rather different as well.
. I love the sound of the Cayin N5ii DAP....but am currently in a position of almost giving up on it due to repeated instances of the, now widely reported, audio pausing/drop out bug and problems scanning for tracks (especially on SD card slot 2). After FW updates, numerous 'double wipes', factory resets etc...these critical problems still remain 
. Another option I've seen is good deals on the 1st Gen Fiio X7 with AM2 amp for under £300. I would be ever so grateful if any experienced head-fi members could let me know how the sound compares with this configuation to the Cayin N5ii..and also how stable they feel the X7 1st gen runs with the very latest Fiio FW 3.3.4 installed. Any advice would be warmly welcomed.
