Going to ask just to get maybe a not so obvious out of the way. You are turning off the main drain when you vacuum right and pulling through the skimmer?
For years I used cheap vacuum heads, part of my "get it right in 2017" program was to take a look at all my tools. Vacuum, filter, hose, test kit etc. Some of these things I replaced (vacuum head) or bought for the first time (test kit, mixing pitcher, 5 gallon bucket, electric scale).
We hired out the basic pool maintenance last year... that did not go well. Hence the "get it right in 2017".
I hated our vacuum head it was cheap and seemed to push rather than suck up debris, but I could not bring myself at that time to buy a vacuum head that was 3x's the cost. Penny wise and pound foolish.
1/2 of the money we paid someone to "maintain our pool" last year paid for everything I bought this year, and obviously other than reagents, everything else should last me several years if not many years.
The first time I used this vacuum head, I was very happy. Believe it or not, I actually look forward to vacuuming now because of the results.
Something to think about, if your end goal is water that looks like glass and a pool that is "inviting" <--great word for us pool owners, spread your equipment costs over a 2-3-4 years (it didn't sting for me when I looked at it like this). For me a $75 vacuum over 3 years is $25 a year to get a result that in the long run cuts down on work time and increases play time, add in the look on the faces of my family when they see "their" pristine pool.
In your case IF time during the week is that valuable, then check with robot owners around the forum, several have them and will be more than happy to share their experiences. Again, spreading the cost out over several years compared to the results you will get will probably come out a winning solution for your family.
Best of luck,
