First off, I have to say I think this bed is fantastic. We paid $3,000 two years ago for a hybrid mattress and it was not this comfortable. However, it is not 'soft' in the traditional sense. Best way I can describe it: the foam is very dense (high quality) which means that if you press your hand into it or climb across the bed on your knees its quite firm. But when you lay down into it, its like sinking into a marshmallow. If you're a heavy individual, even if you prefer super soft mattresses, I'd recommend going to a medium soft or a medium, otherwise you WILL sink in, and it can be overwhelming if you're not used to the mattress enveloping you. I weigh ~240 pounds, but my wife, ~140 pounds, doesn't get this feeling. I used to be a stomach sleeper but our hybrid mattress made this extremely uncomfortable as it had very little give below the pillow top. The softness of this mattress lets me sleep on my beer belly once again and I love it.
Delivery took about 5 days from the time I placed my order. It came in two boxes. We opened them around 5pm and slept on them at 9pm. They were obviously not fully inflated, which took about 3 days, but we had no issues sleeping on it the first night, it was just a little hard. After day 3 it reached its full 'softness' when sleeping. There was off-gassing however it was almost non-existant. The smell itself had a very mild odor and wasn't offensive at all. If you weren't expecting a smell, you'd have no idea one existed. We left the bedroom door open and had no issues sleeping. The smell was entirely gone within 36 hours.
The first night I slept on this bed, I woke up around 3am and thought to myself "Wow. This mattress is so comfortable, how did they do it. I will never buy another brand again" and then passed right back out. No back pain for the first time in 2 years when I woke up. This is our second Christeli mattress in 10 years, and I wish I had of bought another two years ago instead of wasting 3x as much on a national brand mattress. Highly recommend, especially for the price.