I haven't seen the tagalongs often. The trikes are more commong as cargobikes and for the elderly. If your balance is off three wheels give more stability, and if you want to rest a bit just stop pedaling and sit on the bike. The national broadcasting company YLE has often theme nights (long shows on one topic) on various subjects and once there was a "biking night". A retired woman called in and told every retiree should have a trike: one can ride and gossip, and stop and gossip, all without getting off the saddle! :-)
My next post will be a rant about the lousy paving the district heating company did last year. They ripped open a bikeway, fixed some pipes, and did a half-assed work on repairing the damage. Should've fixed it properly, not just tip some asphalt on the ground and spread it around a little.