Has anyone used My Heritage to do DNA test.

Juicy Lucy. Tracing your family tree is highly inaccurate. Even if the mother is known beyond all shadow of a doubt the husband is not necessarily the father. We have to go on the assumption that he is but if this is incorrect then that whole line will be wrong.
I started working on my tree just a few months ago using Ancestry and I have been horrified to see just how many trees have glaring mistakes in them. My great grandmother was married twice. Her second husband had been married before. Of six people who have her on their family tree every single one has errors regarding the parentage of the children. I have certificates and census reports to back up all my findings. If they have demonstrable errors so historically recently just think of the nonsense farther back on their trees.

DNA is unquestionably accurate as I said previously. The interpretation can be wrong but the connection is real.

DNA tests are accurate, no doubt about that. What is not accurate is how it is interpreted. e.g. You may get told a relationship is second cousin once removed. That is on the balance of probability. That the two of you are related is unquestionable.
On the mater of ethnicity the various companies depend on their own databases so their guess is only as good as the range of their customers. As more people join the estimates get more accurate so you can expect to find your ethnicity (as worked out by the company) changes through time.

I was very Puzzled with dna results from My Heritage. I know them to be inaccurate.

I ve done my family tree on both mum and dads side back to late 1600 s and (much to my disappointment ) we were all boringly born in England and mostly around the same county however when my granddaughter did her My Ancestry Christmas present she had no ‘English’ in her results, how could that happen ? I was expecting up to 25%
It doesn’t matter in the least but I m very puzzled by it

My daughter bought me as a Christmas present some years ago a DNA testing kit from 23 and Me.
One of my interests is family history and I have found second cousins via the testing through the sites DNA family.
Totally accurate for me, what I expected mainly. English Irish which I knew about with some German and French which I didn't know about.

Amberone thank you for your reply. I will go over and have a look.

I haven't done any DNA testing but there is a great family history site called Rootschat where there are lots of discussions about DNA testing on different sites, which sites they get the best results from and how to interpret results. Might be worth a look. Very friendly site with lots of expertise to give advice on all sorts of family history related matters.