Most types have the brake levers installed backwards. Often they are butted up against the grips, where present.
Rider can't shift his weight to bunny-hop or for general riding manoeuvres
Heavier than a safety bicycle
Usually an inefficient chain line or the bottom bracket is not fixed in relation to the rider
Usually bigger than a safety bicycle
Lower bike-rider height, resulting in an inferior view through typical traffic and being more easily obscured from the view of others
I hear rumours that recumbents are particularly hard on at least some riders' knees. The significance of this I can not determine.>>1315461
But all of those common every day situations are just a small part of cycling -in general- xddddd.