Both the VR2600 & VR900 are very good wrt stability so you shouldn't have any issues. In case you do, I've found TP Link uk support to be very helpful. In any case you can return the router to amazon within 30 days for a refund or replacement
If you don't mind splashing out, then the TP Link VR2600 is arguably the best modem/router out there currently, it uses a Broadcom modem chipset with 4 stream Mu-Mimo Qualcomm wifi radios. The Netgear D7800 is exactly the same except that it uses Lantiq chipset for the modem so get the VR2600 if you're connected to a Huawei cabinet or D7800 if you're connected to an ECI cabinet.
If the above routers are out of your budget, then the TP Link VR900 is the next best thing, its a superb 3 stream wifi router & uses a broadcom modem chipset. You'll be satisfied with any of these three