I have seen a decent amount of negative reviews and i don't think they are warranted.
I received 99 of the 100 slides. One missing, but no big deal for me, i am using these with a 6 yr old and 3 yr old and a recent microscope purchase.
I am using a mid priced stereo microscope in the 150 dollar range. With this I have had no problem viewing any of these slides.
Not being a biology major, i can say that i believe the slides are all of good quality and well prepared for my level of use. I think they would be of use to more advanced persons also.
I have looked at about 30 of the slides. In all cases there is one of the sample items located at or very near the center of the coverslip. You may need to search a little for the smaller items. In short, the paramecium slide has 4 paramecium set in the center, each stained differently, red, green, and a brown making it easier to see different parts. The insect, daphnia, hydra, and penicillin were all easy for me to examine under various magnification and clearly visible. Earthworm is a section cut through the middle of a worm, stained and internal parts are identifiable.
The storage box is wood, unfinished, well enough made for storage. Minimal padding but fine, as long as you don't drop it.

Several slides were either poorly stained or had barely any well preserved specimen on them.

Good quality

Awesome set to help with wife/nursing student! :)

Nice set of slides. But a lot of them look alike. My daughter (7) rather gather her own things to look at from around the yard and house. It is what the description says.