After some research I decided to get a set of adjustable dumbbells from Weider. Weight of each dumbbell can be selected in range from 10 to 50 lbs by 2.5 lbs step, the set comes with a convenient stand, customer reviews are very positive, price is reasonable - practically all I need from dumbbells is there.
My expectations about it were pretty much satisfied: hand grip is convenient; all critical parts in the dumbbell construction as weight alignment and weight selector are made of metal. Weight adjustment is easy and quick.
From my point of view there is a couple of insignificant disadvantages. One is that the base tray with alignment tabs is made of plastic and it's necessary to put dumbbells back in place accurately to avoid damaging of the tray or jamming. Another is that the weights are not absolutely identical in shape. If they are messed up the holes used for weight setting can get misaligned and make weight adjustment more difficult.
To avoid the problem I found the best aligned combination of weights and put color marks on them:
The marks allow easily to keep the weights in the best order.
The dumbbell set is a space saver indeed as its name suggests and I really like the stand. To reduce pressure on carpet and make it easier to move from place to place I put 4 large Moving Men 8-Piece Furniture Sliders under the stand feet: