Stackable washer/dryer vs side by side for new construction

[Mike Smith]

We are getting closer to finalizing floorplans for new construction multi-family.  We will be putting washer/dryers in our two bedroom units.  Our current plan is to use standard side by side washer/dryers based on advice from our appliance vendor.  However, on much of the new construction multifamily in our area I'm seeing stackable washer/dryer units and even some of the combination units, where one unit is both the washer and the dryer.

We are considering the stackable units because space is at a premium and it would allow about 30" wide of storage that tenants could use.  I feel the combination units are too new and expensive for our market.

I would like to hear opinions of other multi-family property owners on which solution is best (stackable vs side-by-side) and the reasons why.

Mike