The other good thing about 1st season is it is typically draw only, so there will usually be a LOT fewer hunters in the woods (and as mentioned, they may not be as spooked yet - although archers and muzzleloaders have likely been after them). Yes, it is 5 days, but to be honest, I rarely see guys hunt much beyond 5 days on the 9 day hunts - they have either packed and left or they are sleeping in and spending a lot more time around the trailer. One final upside is that sometimes you still catch them bugling - although since they moved seasons back a week or so, it doesn't happen as much.
Downside is it can be hot and dry, with elk not moving around as much and less chance of snow.
As mentioned also - you have to be judicious with your scouting. You don't want to push every patch of timber in the area, looking for sign - you may spook out all the elk in the process. As I mentioned, you can start by watching meadows early looking for animals, but you can also start walking some of the meadows and open hillsides looking for sign later in the morning after the elk have bedded. You'll be able to see fresh sign in the feeding areas if they are around. You can walk the woods just a little bit and try to find some game trails and see how well used they are.
My experience is that if they have good food and water and aren't disturbed, they will stick around for quite a while. Real bad weather (deep snow) and hunting pressure are the most likely things to move them.
Marble has obviously had luck in the timber, but it does take a lot of patience and you have to be "in elk" to begin with. If elk aren't on the ridge you are hunting, you'll creep along for hours and never see a thing. I stalked some timber this year (I used to a lot), and all the wind would do is swirl...it would drive you crazy. I jumped a bull at 60 yards, but didn't have a chance for a shot - which is how it often goes. Marble is right, binos are the key and seeing them before they see you - it just helps (me at least) if I know they are nearby. If not, it's hard to creep at a snails pace for hours only to notice there is no fresh sign anywhere. Since I've found a ridge or two they like to feed on, I like my odds better there than stalking the timber - but some obviously can make it a high probability affair. To be honest, my long distance ridge didn't have a lot of elk on it opening day and I'd seen sign that they were in some timber about 1 mile away. I hunted the timber that afternoon just in case I got a shot, but to be honest, I mostly wanted to scare them out of there and hope they relocated to "my" ridge. I can't sware it was the same bull, but the next morning I had a new bull on my ridge and I'm betting it's the one I jumped out of his bed in the timber. He's now in my freezer
I guess one other downside of finding them bedded in the timber is if you spook them and don't shoot one, they are likely gone for good. You've disturbed their "safe place"/bedroom and they will want to relocate. If they get spooked a bit from a meadow or near a road, they may not panic as much and still stay nearby. But, a bull is a bull, no matter how you gettem - and Marble obviously has his method working.