My first impession of the Ikea cabinet is How (regarding price)? A further look at the product details helps to answer, the backs, the largest part of the cabinet are painted fiberboard. Judging from the weight, I would bet 1/4".

This doesn't disqualify the Ikea as a very inexpensive start, a builder could reinforce the backs with a glued on piece of sheet goods, MDF would be a canidate to keep cost down. Construction adhesives like PL400, Liquid Nails, etc. should work on either the painted surfaces or the melamine parts.

I am atill amazed at Ikea's pricing, though. Their prices are probably 1/3 of what a lumber super-store would charge for the same quality of cabinet. A couple of years back, I saw a kitchen remodel done with Ikea cabinets and it looked very good, the builder had installed some excellent lighting and chosen high quality countertops and flooring. The Ikea cabs were not a detriment to the look. Durability might be questionable.