You just transfer your OSPREY. It automatically gets transferred with all crew and items. You can even transfer crafts using their own engines for free.
Which is tedious (also setting up training all over again), takes enough time that critical missions (terrors and such) are usually not doable that way, you need enough bases and enough ammo and other consumables in all those bases. Plus whatever casualties you take (WIA, even if you savescum yourself out of KIA) need replacing and sick bay slots. And what if you get a bad sanity hit?
In case the mission is not near a base, you can be looking at a day or so before an Osprey gets there (up to ~15-16 hours transfer time plus up to ~11 hours flight time). I've had the
Kitsune arrive at monster terror sites with an hour or two to spare.
One team plus backups works with the Kitsune. One Osprey means you'll miss at least some rather important missions unless the RNG gods favour you. It's also kind of gamey, and you might have seen that I like a certain amount of 'realism' in my X-Com.
Are you talking about time when invasion stars? But Kitsune will appear far earlier then this date. I am talking about pre-invasion time.
Monster terror sites, Blood Moons, some convoys and assassinations if you don't detect them fast enough, BL parties, Mansion defences, some story missions, the list goes on. And what do you do when several of them pop up in close succession?
Kitsune's timing is a problem, as said previously.
The main problems with those crafts is that there is absolutely no reason for a craft to be both combat and troop carrier.
First, a fighter-transporter is its own escort against hunter-killers.
Second, convenience. You don't need a separate transport and you can do the mission right away. You don't even
want a full crew for all missions. I've watched enough streamers move only a few soldiers per turn to know.
And the biggest problem with Lightning is that after few days after you research it you will research Avenger, so why bother with Lighting? May be this 'pop-and-drop' layout is convenient, but more crew is generally better.
Because a Lightning is more economical? You still want
an Avenger, but once UFOs start popping up all over the place, it is no longer physically
possible to do all landings/crash sites with just one craft. Or even two crafts. Flight, refueling, rearming and repair times won't allow it.
That's also more of a problem of the Avenger being too easy to get. Again.
Finally, have you actually
tried the Lightning? The roof lifts are
so damn convenient in the opening stages of a mission. There's a reason why Piratez craft with roof access are popular. Only the Ironfist has something similar, and that craft has its own problems.
Sentinel seems to me like an inferior Lightning, all told. If you need firepower, you want the Avenger anyway.