I've replaced two sets of halogen lights with LEDs -- first on my 2012 Forester, and then on my 2015 Forester.
In both cases the bulbs did a VERY good job of "plug and play" and no real gaps and crap in the light patterns.
The set for the 2012 were actively cooled; they were a pain to get into the light housings and I had to use a rubber boot to replace the hard shell dust cover. That was a real treat.
The assemblies in the 2015 changed so that there's now no hard shell dust cover, which made putting in the new LEDs a lot easier. I went with passively cooled ones, though, and I've been noticing some brightness fluctuation in at least one of the bulbs the last few weeks. It only happens occasionally, but it happens. I'm expecting one of the bulbs to fail sooner rather than later. When it does, I'll replace both with a set of actively cooled LEDs.