This is just a bunch of random things about using ladder line. No particular order to it, just as it comes to mind. It's also not any kind of definitive argument pro/con, every installation is going to be different in some ways, the 'trick' is to figure out how your installation behaves and the use that behavior to your advantage. Sometimes using ladder line isn't the 'best' way of filling your requirements because of how/where you can put an antenna.
First, ladder line, of any impedance, isn't a cure-all. It is less susceptible to damage than coax cable is to standing waves. That's because SWR can produce some really high voltages/currents. While the feed line may not be the limiting factor, other parts of the antenna system can certainly be. One of those parts of the antenna system is the tuner typically used. The physically larger tuners usually have larger components (variable capacitors) which can withstand those higher voltages/currents better than smaller tuners and their components. Wider spaced coils in the inductor(s) mean higher ratings too. So, if it's a 'smallish' tuner, don't expect a lot of power handling at all.
[Tuners are typically rated using Pep rather than AVG power levels. Figure half of the advertised ratings as what you can usually expect it to 'do'. Manual tuners can typically handle larger variations than the auto-tuners. The automatic tuners are only the 'best' when judging that 'best' by convenience.]
Weather does affect ladder line! The characteristic impedance (any size ladder line) will change when it get's wet, covered with snow/dust/dirt/etc, so expect things to change occasionally. Keeping notes on the tuner settings is a handy guide to keeping things tuned. 'Windowed' line is more susceptible to those changes than 'open-wire' type lines, there's just more area to get covered with stuff. The 'open-wire' type parallel feed lines are more prone to 'swarming' on you. Less structural surfaces that tend to keep things from snarling so much. Any ladder/open-wire line will 'swarm to some extent, so just be more careful with it. It's a factor, but not a huge one (until you have to untangle all that @#$%.
Unlike coax feed line, ladder line can't be laid on stuff. Keeping it 3 - 5 times it's width away from metal is a good idea. That's usually something like 4 - 6 inches for typical 1" ladder line, closer to two feet for 600 ohm stuff (4 - 5" wide?). As long as it's kept away from stuff ladder line isn't affected a lot. If/when you run it through something to get it inside the shack it will have 'lumps' of impedance changes. Those 'lumps' are typically not a biggy, a tuner should be able to 'smooth' them out with not problem if they are kept to a minimum.
Using a balun ('remote balun'?) to change to coax to get the stuff to the tuner/radio is the 'weak' point when doing that. The coax used has to be the 'best' you can find, there will certainly be some compromises with that. Keeping that coax as short as possible is a very good idea. If used on multiple bands, the impedance transformation ratio of a balun is -only- a guess, what will be required will change from band to band. It will never stay the same for all bands.
Be prepared to do a lot of soldered connections! I'm not aware of any connectors that are available and that work well with ladder lines. Not really a big deal, but be aware of it.
Anything that has a 'flat' surface is going to wiggle in the wind. One trick to using longer runs of ladder line is to twist it, make it into a spiral looking thingy. That lessens the amount of movement from wind. (Ever wonder why those 'tape' advertising thingys are usually in a spiral? Now you know.)
Can you make 'bends' with ladder line, make it bend around things? Yes. But keep those bends small, never a sharp bend to change it's direction. Hang it with nylon/synthetic/non-conductive cord, or held up off of a wooden 'T', or something.
There are more 'trick', look at all the installations you can find, see how they do things, then adapt those 'things' to your situation when you can.
Having been part of MARS for a long time (was, not at present), I found that retuning an antenna to the MARS frequency then 'making do' on the ham bands was my best way of going about it. Just a matter of priority, and that's up to you. There's more work to it than you see at first glance, but it is very rewarding.
Have fun!
- 'Doc
...runna pile-up on 6m SSB