Looks far more realistic and annoying in Driveclub. And wow at those graphics.

Well the weather in Forza 6 isn't dynamic so it does rain everywhere.  Dynamic weather would have really only been nice in the bigger tracks (the Ring, Spa) most tracks aren't big enough that when it rains only part of the track gets rain.  Anyway the puddles are great since they add a added challenge besides just a wet track.  Also they studied the locations enough so that the placement of the puddles pretty accurately represent where puddles would form in a real downpour on the real tracks.

That entire statement is pretty much false. 

http://www.eurogamer.net/articles/digitalfoundry-2014-driveclub-revisited-is-dynamic-weather-a-game-changer

http://www.thegamingreview.com/8212/2014/12/30/review-driveclub-after-the-big-update/

Both of those articles address the realism of the weather effects and their impact on driving.  Not going to copy and paste, because the volume of data in them addressing your claims is quite vast.  DF compares it to Horizon 2, which is completely unfair, not really making any claims about Forza 6, either.  I am, however, saying everything else you said was untrue.

Lol your entire post is full of assumptions.

Geez...this thread.

You don't need bigger tracks. Rain starts, when do you decide to go in to change the tires, or do you wait it out and gamble it will dry up again. Dynamic weather adds a lot of strategy to longer races. The puddles are indeed great, but if they are exactly the same every time then they're no different from a bump or going over a crest in the track, especially since it doesn't seem the puddles are effected at all from other cars driving through them.
Small steps. GT5 also only had a few tracks with day/night and rain. Forza 7 will likely expand on it's weather just like GT6 did, and hopefully add some unpredictability to it.

After actually playing the Demo:

1. Stupid to compare Drive Club with Forza 6 as a racing game. They're to different.

2. Drive Clubs weather definitely looks better especially the physically (not so) correct rain. But, yeah, there's a but, Forza actually feels more like it's raining. Maybe that's because of Drive Club is arcadier.
Rain drops on the wind shield move to much in DC, you can see to far and way to good when it rains really heavy.

Both games miss the effect of cars realisticaly diepersing mist from the wet tracks. While this effect is a bit weak in FM6 DC just doesn't have it.

3. Framerate: Forza 6 being clearly 60fps feels better than DC or FH2, both being great games. But 60fps just has an impact on detail and effects.

Now, done with comparisons that don't really make sense, looks like FM6 will be a great game. The first round with Ford GT had to much assists. After changing to no ESP, sim, manual shift... FM6 felt slightly more demanding.
Rio just looks great, night races and rain give FM6 finally the variety it has needed for quite some time.
The mods felt somewhat unnecessary though.

Yeah the mods seem unnecessary but we don't know the full list of mods yet so there more then likely will be some that may actually be useful (some of the upper level mods are supposed to make the game a lot more challenging).   The Rio track indeed looks nice would have been nice if they at least had night time racing for that one.  Hopefully all the DLC tracks will have night, day and rain or at least two out of the three.  Super realistic weather effects that cover all weather conditions (snow, sleet, rain, wind gusts etc.) will probably not happen until next generation.

Hope they change the lighting system some time soon. ^^

More night races could come as (free) DLC, as well as more rain tracks.

Snow might be a nice addition, bu before we get to superrealistic weather i'd actually like to have softbody physics all over.

It's really weird with these comparison videos. Every single time I see a forza game, the second I see it, I think "wow, that looks really good!" Then I see driveclub right afterwards, and I remember that nothing looks better than it.