I never took the time to learn how to use it. Am I missing out on anything? I always the FSX Realtime weather. Just curious..

It does things a little differently than the normal FS one, as does the ASE one. The best way to see which one you think is best, is to set real weather for your nearest airport and then look out of the window and compare the efforts of the various engine interpretations of a METAR. Do it for a few different days to give them all a chance at various weather conditions, since their efforts will vary a bit for different weather, fortunately, in the summertime, that's easy to do, since you get blue days, cumulus thermal days, and summer lightning all at this time of year.In my opinion, I think ASE does the best job and the REX weather engine, whilst okay, is not really that different from the normal FS one. Some of that is down to personal preference of course, but being largely a glider pilot, I'm a bit of a stickler for realistic cumulus depiction, and I think ASE does the best job with those, and it has the ability to sling thermals and updrafts where you want them too of course. Bit of a different story if you like flying airliners at 35,000 feet though, where you might prefer the one that you think does the best CB and stratus.Al

The REX engine while great for cloud graphics, IMHO is a pretty terrible weather engine if you want realistic real-time weather depictions. I have yet to see REX depict weather that matches real time METARS and this has been pointed out repeateadly on the forums. It maybe the weather data that they are using or something else. On the other hand, ActiveSky Evolution satisfies the need for real time weather and hardly ever disappoints (unless the primary and secondary servers go down.) The default FSX Wx engine is pretty useless for accurate depictions.It all comes down to what you're looking for.

On the other hand, ASE can't even provide accurate surface winds. ATIS is usually wrong at the destination, so I'm very disappointed with ASE. REX is very good on this point, and hoping it will mature into a complete weather engine.

A while ago I did a comparison between the REX weather and ASA (didn't have ASE at the time). I flew them back to back in the same weather. I used REX for a few weeks to get an overall impression. IMHO, ASA was better. I like ASE as well. I can't say that I have compared the thermals, or the accuracy of the METAR/ATIS against the depiction - it just looked better to me. REX seemed to have a lot of holes in overcast conditions and it just didn't seem as refined. I also like the Active Sky UI a lot more but it may just be because of familiarity since I have been using Active Sky products for at least 7 years - probably longer.

On the other hand, ASE can't even provide accurate surface winds. ATIS is usually wrong at the destination, so I'm very disappointed with ASE. REX is very good on this point, and hoping it will mature into a complete weather engine.

you need to tweak the settings around and ASE doesn't have any of those problems

you need to tweak the settings around and ASE doesn't have any of those problems

I followed all the advice of the developers, including refreshing AI, and still had problems. I do think ASE looks very good; but since my flights always ended with incorrect ATIS readings, and then flying with a tailwind on final, well I had enough. I'd be happy to try it again if they can fix this error.

One thing you should note about ASE: if you use their Direct Wind Control to smooth out winds, it will give incorrect ATIS and winds in the ATIS reports of your arrival runway. This happens because those ATIS reports apply the CURRENT winds, temperature, and Altimeter reading (mb or inches) at the altitude the user plane is flying, not the real values on the ground. This is hard coded into DWC, and won't be corrected. So, if you are in cruise at 35000 with negative OAT temperatures, high winds and contrails, that weather at that point of time in cruise is reported on the ground!! Go to view AI on the ground and you will notice contrails while they are taxing, and planes crabbing like mad because of the high winds.If you don't view AI on the ground or just stay in the cockpit, its not the end of the world, but it does make planning for the correct runway and arrival altimeter reading difficult. So for wind smoothing in ASE, i turn off DWC and use registered FSUIPC to smooth winds. That seems to be the accepted compromise. And I have noticed that ASE is much more accurate in weather depiction vs the REX v2.0 engine.I have another tip, when you are at the top of descent of your trip, you could disable online updates in ASE so that the last reported weather at the destination stays the same throughout your approach and arrival, so there are no surprises or runway changes to mess up all your planning. May not be the most realistic approach, but runway changes in RL are not done so fast as they would be in FSX.