I did a lot of reading about both of these units as I really wanted the best of both worlds, a dedicated streamer that could do more than one service, as well as internet radio, and could rip ALL my CD's for my own collection, and play back in my own private database, and also have the ability to record.
Both units claim to have similar capabilities, except for the record other media function is unique to the Novatron. The Brennan is actually more like an x-10 or x-12 with the CD player built into the unit, as opposed to peripherally optioned for the x-14. Peripheral has its advantages over built ins. If the CD player/recorder breaks, and it will, your'e looking at a much higher repair bill for a built in, and maybe not repairable at all. Yes you can always add another one on to the back,but then you've robbed one of your other inputs. And then there is the dead slot, which bugs me personally. The reviews on this are self evident that the Brennan CD player will not hold up to a continuous ripping environment and will fail. Which is probably why Novatron removed it for the x-14 as well. Even the Brennan company advises using an add on unit to preserve the function of their cheaply designed CD player. But we are only talking about a $10-100 CD player. This point could be moot, unless it reflects similar design flaws within. (I tested a $10 Kangaroo vs. a $100 toshiba, and frankly, I couldn't tell the difference, but I think the toshiba will hold up better. Downside is sucking up 2 usb slots for the power on both. There are other self powered un its out there that only use 1 usb slot. Both suffer from using slow USB-A as opposed to the faster USB-C.
As far as customer service goes, for me this was a big issue for new electronics. I read that Novatron was faster in responding than Brennan, but that could be anecdotal. Novatron is made in Korea, Brennan in the UK. I actually like the idea of supporting private innovating entrepreneurs like Brennan, but when it comes to service, I think the bigger company delivers.
The x-14 backside is much nicer and has more input/output options. As well as wired or wireless internet options with the optional USB dongle. With the Brennan, you actually have to take off the back plate to find the ethernet plug and then carefully run it out through a slot as you put the plate back on. This is hokey IMHO. Why reinvent the wheel?
The screen is bigger on the x-14 and seemingly more user friendly than the Brennan, but probably comparable. I like the CD art icons displayed on the x-14 during play, as well as for cataloguing and searching, which is more like a jukebox style, rather than just lists.
The speaker jacks are more conventional on the x-14. They both are designed for 8 ohms. Be very weary about claims that they will handle less, lest you fry your amp, which is only about 15 watts/channel on these units.
It appears that the x-14 may transmit a more reliable wifi signal to be used wirelessly with another receiver connected to another analogue or digital amplifier, but I haven't tried it yet. You can do wired connection pre-amp outputs using analogue or digital on both, which is great for interconnecting with existing audio stereo/amplifier systems and multiple surround speakers with more power. Both don't recommend using wireless speakers, but it might be more possible with the x-14?
Anyway, as stated above, the reviews for the Brennan seem more scathing than the x-14, but in all fairness, depending on the site, they only pull about 2-3 stars max. So they are not perfect machines, and their hardware/software environment is fairly simplistic and somewhat primitive. After all, the Brennan is built on a raspberry platform circuit board, the same one used to teach kids about computing.
The biggest difference is the hardisk memory capacity. The x-14 can take up to 8 TB, whereas the Brennan only about 1-2 TB max. And the cheaper models of the latter only use SD memory cards, which to me seems like a rip-off. Yes you have to buy the disc or sshd on the x-14 separately and install it yourself, but its very easy, and the company will walk you through it. To me it was worth it. And the price is cheap for 1-2 TB. And if you want to increase later, you can import the pre-existing DB. You cant do that with the Brennan.
So, for me the choice was logical, I went with the x-14. But if I had more money to invest, I would have went for the x-50. I'm waiting for the touch screen version ;-)