1030 + gradient issue

I do not have such a problem.
There is indeed a slight delay, but it is insignificant.
All brands of bicycle computers have such delays in the output of information.

I‘m happy with my „rubbish device“ 1030+ and have none of your problems 
(ok, I don‘t use Strava)

No ,810 had not any delay, I had it and it was crazy instant

I also have the same problems as you. I contacted Garmin assistance for the gradient delay (about 20 second) and despite having changed the device I still have the problem. It’s very annoying. I have been informed that there is a worldwide report and garmin is working to resolve it. what did they say to you?

Tengo los mismos problemas con el GArmin edge 830 , tambien marca mal la temperatura sobre 4 grados celsius mas alto de lo real. 

I have the same problems with the GArmin edge 830, it also sets the temperature wrong about 4 degrees Celsius higher than the real thing.

After 18 days waiting, GARMIN has responded. The only answer now is, that according to the information I give them, I have to send my device to their facilities.
Just this, not a single word about whether the bugs are common or not, whether they are fixing it or not.
They also don't tell me if they are going to try to repair the device or send me a new one.
What would you do in my place?
Would you require a garmin commitment to pay me back? since from what is read in the forum, are general failures, with which the new one that they send me will be just as bad. or even worse, send me one repaired with the same faults and on top of that it would no longer be new and with a shortened warranty.

Regarding gradient, I would like to put that in the same basket as VO2max and temperature.

Garmin tries to give us its best estimate, but you have to understand how (in)accurate the value is.

For gradient: even using GPS and barometer, a grade value over a short distance will always be very inaccurate.

For temperature a measurement at the device can never be accurate (alternatively you can use a 'tempe' sensor under saddle).

For VO2max if your heartrate is all over the place (like mine) the value is inaccuraty estimated.

We have to understand how things work to work with the values.

To me these things are nice to haves. There is not another device that *can* do it better.

I would certainly NOT send my device in for any of these issues.

Cannot comment about the speed sensor or map issue.

Well then, that GARMIN give me my money back and everyone is happy, the previous models 1030/820 / 520plus etc, do not have these problems, that is, it is not a matter of technology in general, only of these last models in particular. At no time does GARMIN notify when selling that the device has functionalities that do not work. They are joke, joke functionalities.
GARMIN should put a big label accompanying their sale:

"ATTENTION DEVICES WITH BETTER BATTERY AUTONOMY BUT WITH MANY JOKE, TOY, FUNCTIONALITIES.

PURCHASE AT YOUR OWN RESPONSIBILITY.

Coming from an 800 and 1000 I can assure you that the 1030 plus responds to changes in grade at a very noticeable slower rate on roads that I know well.