You commented that you don't want to be too warm.......I never worry too much about this, as I can always either shed some clothes, or else push the the bag down off my chest or stick my feet out the bottom.
I had a brief flirtation with trying to run my sleep system as light as possible, but gave it up on trips that I want to enjoy the travel and sleeping, as opposed to trips I just want to push through. ie for a 24 hour rogaine, my sleeping bag is a wheely bin liner and my hat and jacket. But for a weekend out in the snow at St Gwinear with the kids, I'll take a WM Summerlite and team this up with a lightweight down puffy (First Ascent) and maybe a pair of MB puffy pants if I envisage an outdoor snow kitchen.
If I'm pushing up Feathertop or Bogong, on a long day with sh*tty weather, I'll take the WM Apache for an extra 350g, with similar clothing. It's worth it to me, to be sure that I'll get a good night's sleep and enjoy the next day.
So for three season I'd be inclined to go WM Summerlite or similar, or a similar quilt. This works for me, with clothes for a hard frost or with dry base layers for cold hard rain. I could maybe try to go lighter, but I'm not sure why. There may be a seriously good 10 degree celsius option out there, but unless it's under 360g (12oz) and under $300, I'll take my weight savings somewhere else.
I've also found that a very big contributor to overnight comfort is dry sleep socks. I HATE socks in bed at home, but when I'm pushing the limit of my bag, I find dry socks a huge help. Thickness isn't important, as my dry woollen running socks are much warmer than slightly sweat damp, thick woollen hiking socks.