I’m a bit of a minimalist, and try to keep my luggage as light as possible. Luggage tends to sit pretty high up on the bike, raising its centre of gravity. This results in worse handling on the trail and, due to the longer lever from the COG to the ground, more energy required to pick up the bike after a tumble. Either way, tackling boulder strewn riverbeds or technical trails is much more enjoyable with a lighter bike.
The priority is to keep moving and I will sacrifice personal comfort for a functioning bike. I’d rather carry more spare parts instead of camping luxuries. Camping essentials should be as light as possible. I do not go to extremes though, like drilling holes into my toothbrush or welding custom spanners and such. Having said that, I must admit to having an irreplaceable MSR titanium spoon from my climbing days.
In addition to weight, another issue to consider is equipment volume. Careless selection of especially camping gear quickly transforms the gnarly adventurer into something akin a Cambodian street vendor. Anyhow, I try to get away with as little volume as I can. It helps keeping the bike streamlined and the centre of gravity lower.
Sleeping pads are light, but can add a lot of volume into the luggage. In terms of reliability, I’d rather carry a foam pad, but they are just too large. So I use an inflatable pad and carry a repair kit. Instead of a full length pad, I use a 3/4 length narrow self-inflating Thermarest. It packs into much less space than a full size pad. The main function of the pad is to insulate the torso from the ground. I use my Gore-Tex riding gear and fleece mid layers to insulate my feet and head from the ground.
For sleeping bags, I prefer down over synthetic. Down bags are lighter and pack into smaller space. The snag with down is that you have to take extra care to keep it dry. For extremely humid conditions a synthetic bag would probably be the sensible choice.
Adventure riding off-road and in technical terrain is energy consuming and hard work for the body. Getting a good night’s sleep between days on the trails is essential for recovery. Being too cold or too warm will make it less efficient. I prefer to select a lighter sleeping bag and use my mid layers for extra insulation if necessary. My summer bag is a Marmot Always Summer which is rated at 6.3°C/ 1.5°C comfort/low. I’ve used it in as cold as -2°C. For winter I use a The North Face Blue Kazoo with a comfort rating of -10°C.
I usually carry a Sierra Designs Clip Flashlight solo tent. It weighs just over a kilogram when it’s dry. I rarely use it in cold weather, when temperatures are too low for insects to survive. Another option for when the bloodsuckers are out of business would be a bivouac bag or a survival blanket. Anything to keep you dry in case it rains.