I have never been a fan of long term storage, the decision to put mine in was a bit financial and partially so I could try some other cars while I had some spare money.
After 2 years in a well controlled storage area and 19 months in a non heated, non de-humidified garage my opinion has changed slightly but not by much.
One thing I always liked about the Merc was how even after a few weeks of no use within 5 miles it felt fine again. My Peugeot and Diesel Golf before it always felt cold and damp and took a while to get heated through. It never felt very nice and made getting back into the car a bit dissappointing.
When the car was in a controlled storage place, after 2 years it felt normal, i'm not 100% sure if this was just a result of a big barn and lots of airflow or the fact it was a warmer space.
19 months in my garage at home, which is relatively small and not 100% watertight as you can see small damp areas along 1 wall ended up with the car feeling pretty crap.
The suspension was tight and a little crashy, the brakes felt absolutely awful, the engine was a little rougher upon start up when in cold running mode and on a couple of ocasions threw up some faults and went into limp home upon starting.
It took a couple of tanks of fuel and some long drives till the car felt normal again, which makes me wonder what damage was done or how much life i've removed from bushes, fuel lines etc.
The new garage will be de-humidified and have some heating to keep the chill off definitely.
So, proper car storage with a good flow of air around the car = good. A normal garage = bad, unless bone dry or with some form of climate control.
I was quite surprised how the Merc of all things felt when I first got it back. It certainly doesn't change my opinion on using cars properly, it definitely does them good.
I came here to drink milk and kick ass..... and i've just finished my milk!!!!