There's something that can add extra comfort during the night, which believe to be equally very important for a good sleep: the mummy sleeping bag, because:
1. No sleeping bag is good enough to protect you from the ground - even the most expensive one won't keep you warm if your warmth is lost directly to the ground - you *will* be cold. The sleeping mat is mandatory to insulate you from the ground.
2. Generally camping mats are good enough - even the cheapest one, all made of insulating materials. BUT not all provide equal comfort - the ground is much harder place to sleep compared to your bed, which you will long for shortly. So I found the solution in the *inflatable sleeping matresses* - they provide good insulation too, but most of all - add pure comfort added to being just warm and hard on the ground, which for me was also hurting on my sleep.
Those have different options - cheap means heavy or thin. The best value offer I found and serves me great for years now is the NeoAir inflatable matress - it's probably the lightest on the market (at least was when I bought it) and is 2.5" thick, which you can really feel, especially if you sleep on one side/shoulder.
I believe the sleep and warmth are the most important things for a goodhike experience for more than a weekend.
You can add warmth also with thermal underwear - options are wool and synthetic - both are good and serve well when wet. Wool, of course, is the more expensive option, but also has advantages: less bad smell over time not being washed, but is less durable. I'm not sure it worths the extra dollars if you spent them on down sleeping bag, but definitely get the underwear too - it is handy also during the days in severe weather conditions, together with a windstopper jacket.