Disclaimer: I am only level 6 and about 6.5 hours in the game (stupid full time job). That said so far I am having the opposite experience. I am following along the main quest; Goodsprings -> Primm -> Nipton (just finished in Nipton) and so far I have had almost no challenge. I have been sticking to the road, not trekking cross country, and the hardest single enemy I've had to fight so far was a Gecko Hunter. Primm was a little difficult when I first got there because I got swarmed by about 6 or 7 guys, but I got through it and the rest of that quest was easy peasy. Compared to FWE in FO3 this game is a stroll in the park.
Well, obviously if you stick to the main quest and follow where the game tells you to go, you're not going to be running into Deathclaws and Cazadors around every corner; that would just be silly. Obsidian may have set out to make the game tougher but that doesn't mean throwing impossible enemies in the path of the main quest. If you want to explore the wastes before you're ready, you can; just be prepared to deal with the dangers.
I've found that a change in tactics does indeed make all the difference. I remember going through that valley just beyond Nipton, and the first time I did, I got ambushed by raiders. I
probably could have taken them, but they killed ED-E so I was like [censored] that and reset. Then I snuck up onto the ridges and killed them all without any of them even seeing me.

Of course, with some enemies at some points in the game, the only strategy is to run, pray, and change your pants if you get back to safety.