Oh, that is a hard question. Demanding in terms of employee commitment.
Let me say that I speak only about direct knowledge: either places / jobs I've worked, or where my friends work (or at least acquaintances with whom I am close enough to get the real story.)
The same company and a similar role (for example: hardware / software / firmware / chip design engineer, fairly junior level, ~0-5 years of experience throughout the BS-MS-PhD range) can vary drastically. Generally speaking, the more visible the job, the more commitment. With that said, more visible jobs also tend to get more funding, and therefore more people to do the work.
People work between 30 and 60 hours in these roles. Older folk tend much more towards 30, because in their 30 hours they can do more than newbies can do in 60. They also tend to work schedules that are much more kid- and family-oriented (lots of working from home when a kid is sick, lots of leaving very early but then popping back online for a few more hours, that sort of thing.) Very few people work more than ~50 hours, though some who haven't yet figured it out are _at work_ for more than 50 hours.
I would say that the absolute worst conditions, as far as demanding commitment, in the valley are for the following two groups:
- Software developers at startups
- Game developers, especially code monkeys
I would choose to be a startup guy over a game guy any day of the week, even if the startup paid half the salary. Seriously: game developers have it really, really bad, with very few exceptions.
AAA titles generally require 60+ hours a week, non-stop, until the game ships, at which point a large portion of the team (or the entire team) gets axed, and need to find new work. They pay salary, so no overtime benefits. They might feed you, but it's usually going to be pizza, so you're going to gain a lot of weight and lose a lot of hair. Pay's shit per hour. No chance of being adequately rewarded for a fantastic product.
On the other side, mobile games generally also require a lot of hours, but mobile gaming is really, truly terrible, with very few exceptions; so the work is going to be even worse, the product not something you're proud of, and there's a good chance the company will go bankrupt.
Mobile app startups are generally very poorly funded, and require a huge amount of hours; so your pay is shit. Usually the apps are very basic, so there's little barrier to entry into the market. On the plus side, there is a huge potential upside, either from funding, or from being acquired.
"Real" startups that aim to sell a real product require a huge time commitment, but apart from having low hourly pay and high chance of needing to find another job due to the company folding, it's actually a good gig if you're young and spry. Your potential upside is very large, and not tech-bubble large; if you end up selling a million (or ten million) widgets, that's real money in the bank; or if your software starts being used by a thousand companies who all pay, that's real money in the bank; you're not just building a large user base in the hopes of being acquired / funded. Even if you end up with nothing, you've still got the experience of wearing every hat, being a developer/engineer with broad knowledge of hardware and software, and seeing how companies run (and how they fail.)
In comparison to that, established companies like apple, intel, microsoft, amazon, amd, nvidia, samsung, qualcomm, etc etc etc etc, are all relatively low-stress and allow you to choose a time commitment that works for you.
tldr established companies are all decent, some are worse and some are better, but it largely depends on team, visibility, and how well funded your particular organization is. Startups are hard, but have great upsides and even greater potential upsides. Game development is the real area that you never, ever want to work in, unless you're a complete masochist with no family and nobody to care if you kill yourself.