Close proximity to a wall, ceiling or floor will reinforce the bass due to reflecting sound waves regardless of the speaker type. The room layout, the exact speaker placement as well as the material of the wall, ceiling, floor etc. all affect and color the sound produced by the speakers.
This coloration can both be a disadvantage, especially if you are not conscious about the effect, but can also sometimes be used positively to deliberately boost the low end.
Very few people have completely neutral speakers set in an acoustically ideal room--this is true even for professional studios with otherwise state-of-the-art equipment. It's much more important that you know the effect the speakers and the room have on the sound. Of course you want to get rid of pronounced artifacts caused by standing waves, but beyond that you can create stellar mixes in many environments as long as you know how the speakers and the room color the sound.
For example, the venerable Yamaha NS-10 has been a long-time near-field monitor favorite in many studios despite a reputation for a sound that people either love or hate, but nobody would claim to be neutral.
I use a set of reference CDs with a sound that I am intimately familiar with and that I trust is sonically well-balanced. I know how my reference songs sound in a wide variety of settings ranging from crappy mono transistor radios to my beloved studio monitors and I play these songs a lot on my studio monitors as a way to reset my ears.
As long as the placement and the room doesn't result in standing waves and other problems that completely masks other detail in the sound, then you will probably be fine as long as you know how the placement colors the sound.
Buy the speakers at a place that'll let you return them if you don't like them and see if it works for you.