Another change of router.

[#1]

A quick question.
I've had enough of the Billion 8800 AXL, it's inadequate for my needs in that the Wi-Fi extenders are useless and without one I can barely get a signal downstairs, so I've bought an Asus DSL-AC68U to replace it.
Will it cause any issues to my connection speed, doing a change over in say 30 minutes of so, will the DSLAM go into overdrive and screw my speeds up again?
Your thoughts & advice would be appreciated.

[#2]

I have the DSL-AC68U, I changed it on Friday night, after a BTO engineer spent over 2 hours proving I had no problems with my line other than an ECI modem on a Huawei cab.
In a period of just over 24 hours it was stopped and started a number of times by he BTO engineer, then in the evening I rebooted it perhaps 3 times:
Once to change over the modem
Once when I updated the firmware to the latest (very important to do this, I tried to do it before attaching the new router, but no go)
Once when I changed some of the settings.
I think I changed the settings again on Saturday and rebooted on Sunday (to finally regain my speed).
I went from 60 on Friday morning to 52/3 on Friday evening after attaching the new modem, on Saturday morning (after a system reboot) my IP reverted to 78, but my speed stayed the same until I rebooted on Sunday.
I reccommend you work out what you want your settings to be before setting it up. Let me know if you want a copy of mine.

[#3]

I have a DSL-AC68U, I bought it replace the BTO Modem and PlusNet router combination because I felt that speeds were falling and the reviews suggested that the 86U was both faster and more stable.
It is certainly more adjustable, with a number of tweaks possible, and whilst this is a good thing overall, I am concerned that I could (and possibly have) set it up badly. Looking around, it seems impossible to find the correct settings for one's connection. There are many suggestions, some which have worked well for others seemingly, but how do I know what is best? I have changed some settings bit by bit over some time to see what happens. You cannot keep changing settings because you bring DLM into play if you do. Changes should be few and far apart.
If it was possible to set up and then activate like a "fit and forget" BT modem, I would be happier. In fact Mantaray suggested some changes to my settings yesterday which I implemented to match his. So far so good, certainly no worse, possibly 1Mbps faster but hard to say for sure. I lost speed (about 10%) when I upgraded to the latest firmware about a week ago, and I emailed Asus support. This afternoon I had a reply from them suggesting that there could be a bug in the latest firmware and suggesting that I downgrade to the previous version whilst they look at it. There have been 3 or 4 firmware changes since I bought my AC68U in January.
I swapped back to the BTO modem briefly and its slower, plus I don't think it's G.INP enabled, and I think my cabinet is, but hard to tell other than with it enabled on my AC68U I see improved speeds and fewer errors. (I have currently 1 CRC error Down, in 10 hours of operation, I get the odd CRC Down occasionally, I never get one UP, but have no idea if this is significant). I'm annoyed that VDSL2 seems to be a "black art" rather than a proven science, that speeds start good and deteriorate, and that BT downgrade what is acceptable once original speeds are no longer delivered. I suspect that they have lost a small fortune sending out Engineers again  and again in the last year or two to sort out speed issues. The reason is that the more the sell the slower it gets with crosstalk interference, it seems, and they are slow to implement solutions.
Hope that this helps.

[#4]

Thanks folks.
I think that I'll leave the router in its box unopened for the time being and wait and see if they produce a new stable firmware for it, before I try and install & configure it. The 8800 is working and I have a small low powered WiFi extender on trial at the moment and it's working well.
If it continues to do so then I may return the router to Amazon unopened.