It really depends on what you need them for. There are things they do very well, but there's also things they do pretty poorly, and if that's what you need, you're not going to be happy with their performance.
First thing to remember about remotes is that they're a lot like NARC beacons, in that the unit deploying them has to get in to the target area, possibly putting said unit in harm's way, and also delaying any use you get out of the remotes until the deploying unit can actually get there. Fast units will get there in no time, but if the enemy's already there, they may not survive the trip. There are some big units with sensor dispensers, but they're proportionately slow, so the trick is getting them there in time to do some good. Fortunately, you can try to drop off your sensors long before enemy forces get to the area, but this of course requires you to predict where the fight is going to be.
Once deployed, remote sensors have two real uses: Detecting enemy units, and spotting for indirect fire.
Detection is done in three ways(two really, but one can be split into two very different roles, so I consider them separate):
- The remote sees units you otherwise would not have LOS to. This is most useful in double blind games, where you can drop off remotes in useful locations and have your manned units move on, greatly expanding the number of "eyes" you have for finding things and similarly cutting down on the number of hiding spots the other guy has access to.
- The remote sees units you don't have anyone close enough to see. This is basically the same thing as Option 1, but on a strategic level. Instead of dropping off a sensor to see if an enemy 'mech moves down a particular city street, you're placing one near a major highway or in a mountain valley, to see if an enemy battalion passes through. This has the advantage of greatly expanding the area your scout forces can monitor simultaneously(so waiting until a patrol passes before sneaking through ceases to be useful), but also exposes your scouts to much less risk. The cost of replacing even a handful of remote sensors is far less than the cost of replacing even a cheap scout car - and its crew.
- The remote has the ability to detect hidden units in the same manner as an active probe. This is pretty hard to use, for two reasons: The sensor's detection radius is very small, and obviously, it is immobile. Unlike any other scout in the game, once deployed, it cannot move if it doesn't spot anything, you have to be lucky/smart enough to drop the sensor almost right on top of the hidden enemies, or drop enough remotes to cover the entire map. On the upside, most maps don't really have all that many suitable ambush points, so you can narrow things down pretty quickly. Also, don't forget that while it is technically advanced rules gear, remote sensor technology isn't one that was lost during the Succession Wars. Unless you're lucky enough to get some of Liao's then-new Ravens, this lets you do stuff that is otherwise impossible until the Beagle Probe gets reintroduced.
Just like detection, remote sensors can be use to spot for indirect fire in multiple ways:
- Remotes can spot for LRM fire just like any manned unit. They're pretty bad at this, imposing a stiff penalty on what is usually already a tricky shot, but the very fact that you can do this without exposing a manned unit can be pretty useful. Don't expect to kill anything or even hit much, but the sheer fact that the targets are under active fire can force them to stay on their toes, and lucky hits do happen. This is Battletech, after all.
- Remotes can also spot for artillery fire, and they're actually better at this than LRM fire. I'm not really a fan of using artillery spotters in tactical games, but that's usually because most games I've ever seen are too fluid and fast-moving for me to ever need to hit a single hex more than once, or to even take the time to zero in shots in that manner. It is useful for some people though, and for those, just like LRM spotters, there can be a benefit to spotting without exposing manned units.
- To me, the greatest potential for remote sensor spotting is in strategic artillery spotting. Just like strategic detection, this is about having a remote see an enemy force go by, and you being able to drop shells on troops that are not expecting combat. While you can guess that the other guy is moving through an area and try to blanket the whole mapsheet in HE, having a remote sensor present means you know he's on that map, and even know which hexes to aim at. Scatter will continue to be the pain it always is, but this will allow you to cluster your shots for best effect, instead of going for blanket coverage in hopes of hitting something.
All that aside, remote sensors do have their weakness that you have to take into account, lest they turn out to be useless to you.
First off, a remote sensor is a short-term solution to any problem. They're very immobile and VERY fragile, so any given sensor that pisses the other guy off has a lifespan measurable in moments. Don't expect to get more than one or two turns' use out of any given sensor in any tactical game, so if you want constant coverage of an area, you have to either drop a LOT of sensors, or keep dropping new ones to replace those you've lost.
Second, remotes are easy to jam. Not only will any form of ECM covering a remote cut off the signall, so will any ECM covering the manned unit monitoring the sensor, or any ECM blocking a straight line between the remote and the monitoring unit.
Finally, remotes still need people monitoring them, and any given unit is very limited in how many remotes it can monitor at once. Units can mount gear that can handle multiple feeds like Comm Gear, Active Probes, or C3 Masters, but on average any given combat unit will only be able to monitor a single remote sensor per turn. This means that you could easily find yourself having a battlefield seeded with over a dozen remotes, but only able to receive data from three or four of them at once, forced to ignore the feeds from the rest at that moment. If this happens, you have to decide which remote sensors you're going to monitor, and which you're going to ignore in any given turn. Choose wisely.
