I'm currently testing both the MR600 and B535 to decide which to keep. I'm on Three and the best signals are in my loft. I live in rural Somerset, a few miles from the tower that both routers pick up, and tend not to suffer from too much contention.
I can't make any comment on their wi-fi performance as I disable this and use access points connected via ethernet.
MR600 is running the beta firmware v1_1.1.0_0.9.1 available from the TP-Link community site that allows band selection. I have attached the bunny ears that came with it - signal quality suffers without.
B535 is running 10.0.2.1 firmware out of the box. It seems to have a better signal without bunny ears.
The MR600 ran faultlessly for over week while I worked from home - video conferences never dropped. The kids can game on both PS4 with voice chat and the Nintendo Switch which is notoriously fussy given the P2P nature of its online service. I watched Solo on Disney+ which it says is 4K and YouTube usually defaults to 720p.
Having had the B535 for a few days, it has matched the MR600 for stability, but I will run it through next week for a proper test. Should probably watch Rogue One to continue the Star Wars comparison.
To answer queries from @barker04 in another thread.
1) Speeds compare
Very similar. Both achieve maximum of 60 down and 30 up, more typically 30-40 down and 20 up. I would say that the MR600 appears slightly more consistent on speeds, but given all the factors involved I'd say there's no difference.
2) How stability / signal strength compares
Both achieve 4G+ on bands 3+20. Forcing any other combination using the MR600 interface or LTE H-Monitor proves pointless. SNR hovers around 10, RSRQ around -9, RSRP around -100 - not great!
3) How UI compares
The MR600 is more user friendly, though ultimately doesn't given you much more if you're comfortable using LTE H-Monitor for the B535. I really appreciate that you can reserve loads of IP addresses on the MR600 (I'm up to 24 with no idea of the limit), whereas the B535 only allows 8 I believe. Of course, most people won't be bothered as DHCP usually handles things fine.
4) If you are running the new firmware to allow band fixing? As I want to do this
Yes, and it seems to work, although you can't guarantee results as it's the router requesting a band from the tower. The MR600 is faultless in always securing 4G+ on 3+20, whereas the B535 seems much more picky - often getting just 4G on band 20 with really slow speeds. Using LTE H-Monitor I have fixed 3+20 which has secured 4G+ so far.
5) Which you would recommend
I genuinely can't answer this yet. I would be happy with either. Interesting the number of issues with both you see reported on various forums. I understand the MR600 beta firmware includes a number of other fixes for issues that probably caused problems for early adopters back in 2019. I don't think I've seen the page stalling on the B535 that many people reported early in lockdown - but time will tell.
What this has mostly taught me is that trying to get fast, stable 4G can be incredibly tricky. Moving routers or their aerials by a tiny amount can have a significant impact. If I place the B535 at a slightly different angle and reboot it, I get 4G only on band 20, hopeless speeds, and am on the verge of returning it! But then move it a little using signal readings to check placement, lock 3+20 with LTE H-Monitor, and it's a great router.
For sure the MR600 has been far less fussy about placement.
And FWIW, the design of the MR600 itself is better. Can be laid flat or mounted on a wall thanks to the placement of its ports. The B535 with cables sticking out the back won't allow that.
Happy to answer any other questions. I don't use advanced features, so won't be able to comment on any of those I'm afraid.