Whilst it's quite fiddly to build an encounter from the blocks provided in these dungeon tile sets, it's quite easy to throw something together if you're improvising. Certainly, I've found it useful to have a few boards to hand in case players do something unexpected. Dry markers appear to wipe off without marking the tiles.
On the other hand, creating something specific will take more time and thought - using tiles doesn't excuse a DM from including interesting terrain for players and monsters to work with.
This particular set features grassy fields, a small 'camp' as well as some road and river pieces and is the set I've got the most use from, being both general in style and a common location type.