There is no magic bullet, no "right" answer.
I am an architectural/industrial photographer from an advertising background. I'm based in the Middle East and work for high-end clients from Europe, the Middle East and Asia.
I think a point I haven't heard discussed yet here is what your personal brand and market position is, and more importantly, how your chosen method of presentation reflects (or contradicts or confuses that).
It's important to have some understanding of this when making your decision.
I run a multitude of tools, each with slightly different key functions. I say "key" because these functions overlap a little.
Firstly, I agree with the post that said if you don't have a killer website, you aren't in the race. Agreed. However, have you thought about what your website is trying to do for you? Is it your primary portfolio by default? Is it a teaser? Is it a door-opener? Is it your deal closer? Have you considered who your key audience is and how they might respond to your site? How many fashion shooters (for example, not singling you out) sites have you visited which show image after image of beautifully executed close ups of pretty girls, on a plain (this week, white) background... What would that say about you and is this what you want it to say? The problem is that often, all it says is that you know how to light with a beauty dish and reflector. If that's all you have to say, how does putting it on a website (or iPad) get you the gig?
I treat my website as no more and no less than a statement of competence, hence it has a small number of images from less important disciplines, and more of my core business area. No spiel, no fuss, but this guy can shoot - that's my brand. What's yours?
At actual formal folio presentations (I never use an agent, I give my clients facetime. I sometimes take my producer), I present printed folios, not an iPad. I agree the iPad is convenient, trendy, interactive rah-di-rah-di-rah-di-rah. I'm a high-end, expensive, experienced shooter with lots of attention to detail. The qualities attributed to the iPad presentation are not what my brand is about, so for me, as much as I love the iPad, it's a no-no. Besides, the screen simply cannot give my clients the Wow factor that a print from an 80MP back can and does. Keep in mind, though that the key decision-maker for my services is usually a senior exec of a major corporate, not a 20 or 30-something art-buyer from a mag or ad agency. Play to your audience. Just remember though, if you are playing the same instrument as everyone else, your message can get lost in the din.
Understand very clearly what it is you are selling. I do not sell pictures. Yes, I mean that. If my client wants to buy pictures, they can go to any one of hundreds of Guys-With-Cameras (don't be one of these!) who've ever pointed a camera at a building or oil installation. My pictures are simply the end-product of the thing that I do actually sell my client. So what is that exactly? I tell my clients that they pay for "all the weird shit (I actually use this word) that goes on in my mind prior to the final image materialising".They are paying for a creative solution they cannot buy from someone else. So, what is it that you are selling? How is it different from what all the other camera operators are selling? Most importantly, how does it help your clients' brands stand out from their competitors, in the eyes of their customers?
My folios are carefully printed, relatively small (8.5x11in) and tailored to each customer I see. The important thing for me is to make the meeting about the customer and their communication needs first, and about my work second. The non-verbals are very important. I am selling creativity, reliability and professionalism based on skill and experience. I use a printed folio, simply but beautifully done, shown with confidence but no fuss, in person. It says to the client "You are important to me". If my work is not good enough, obviously, none of this works. But if it is, then they have a whole bunch of additional reasons, beyond the images, to work with me.
To those who would say the approach of an architectural/industrial shooter won't work for an ad shooter, I'd point out that I shot ads for global ad agencies for 25 years before choosing my current speciality, using pretty much the same strategy. I did 1 to1's with art directors and creative directors as well as art buyers - with printed books.
If some of my remarks seem provocative, they are deliberately so. How you show your work is one of the most important decisions you will make. Do what you will, but make it a considered decision.