Any general observations using Metrorail in Mia to commute. Is it relatively pleasant or more like the NYC subway at rush hour.

Metrorail is a heavy-rail system (similar rolling stock to the Washington DC Metro) that has a singe major line (with spurs, such as the line to and from the MIA intermodal center). All tracks and stations are above ground.

The limited area of route coverage means that your starting and ending points must be near a station to make full-time commuting feasible. The Metrorail stations in the downtown area mesh with the MetroMover (a robotic people-mover system somewhat similar to the CDGval), which brings passengers closer to many offices and hotels in the core downtown, Brickell and Performing Arts Center areas.

If you live in Eastern Broward or Palm Beach counties, it is feasible to take Tri-Rail south and change to Metrorail at the combined Tri-Rail Transfer station. You need to carefully check schedule times, and weekend service has less frequency. The time of a combined Tri-Rail / Metrorail commute is lengthened by the fact that the Tri-Rail tracks run near I-95 in the northern counties but must swerve several miles inland (westward, away from the ocean to reach the transfer station and ultimately MIA) (this is because Tri-Rail uses existing CSX freight tracks).

This is the key. If your origin and destination are along the metrorail /metromover corridor the commute is fine and very doable.

Any additional steps such as Tri-rail/buses/driving to station etc it will probably be more trouble than its worth. Any idea on your origin and dest?

At this point the potential is the very southern part of South Beach or Biscayne Blvd to Kendall right near the South Dadeland (Kendall) stop. So what is better driving the entire way which is going to be 15 to 17 miles OW or drive to a Metrorail Station.

From south beach it would be best to just drive the whole way.

From Biscayne or from Brickell if you are near either of the metrorail stations (govt center or brickell) or near a metromover stop(connects to metrorail) then i would take the train. On normal days the time savings wouldnt be huge but much less stressfull than driving on US1 at rush hr every day. And anytime there is an accident or other delay on US1 you will come out way ahead timewise.

Unless you are dead set on south beach or Biscayne i would take a look at Brickell. Plenty of new buildings a short walk from the Brickell metrorail station so would have easy commute to Dadeland as well as painless train service to MIA for two bucks.