Reglan (and droperidol, for that matter) fell from popularity due to their respective black box warnings. Which may or may not have been fairly applied depending on who you talk to. Phenagren has some nasty side effects including phlebitis and a tendency to give older folks dystonic reactions (I've seen elderly patients pretty well flip their wig post phenagren, not sure why it seems to effect the elderly so badly).
Xopenex is an expensive drug that does basically what albuterol does. It is more beta 2 specific than albuterol, but it's still under patent so that specifity comes at a price.Used primarily to prevent long-term sympathetic stimulation in people who don't need it and in kids who have behavioral problems in Ventolin. Ipatropium on the other hand is a great addition to any drug box as it helps with acute broncospastic events from an entirely different angle.
Valium actually has the longest half life if all the agents listed. It's also the "weakest". I personally like midazolam simply because of the IN admin option and the tendency to induce anterograde amnesia, as usually when we're giving it something unpleasant is happening. Lorazapam is a perfectly ok agent and has less hemodynamic effects than midaz.
IV NTG is the bees knees IF you have a pump. It's not a drip you can eyeball. It's also about a hundred bucks a bottle, so it's not the cheapest stuff ever. I've personally probably hung a few gallons of the stuff and through urban, suburban, rural and HEMS have never had an issue with the glass bottle other than Minimed pumps throwing a fit over sucking minute amounts of air. If your really worried about it, get a Koozie, cut a hole in the bottom for the bottle neck and carry the NTG in there. Works like a charm.
Hopefully this was helpful.