For us, GoCardless win in every respect except for scope: the bank accounts they can charge have been limited to UK only and are just starting to expand out to other countries in Europe, but global sales aren't possible for now so you need at least one other option if your customers are worldwide. No complaints so far in terms of integration, support, fees, or legal terms though.
Braintree is our other current plan: there's a multi-week time lag and the hassle of providing significantly more information up-front when you apply, but like GoCardless they seem to have good support and the information they ask for doesn't seem to be unreasonable, just time-consuming. Also, unlike a lot of payment services, their legal terms were quite short and so far red-flag-free. The fees aren't bad, but they need to sort out their presentation so they don't refer to obscure bank interchange rates rather than giving a straight answer on percentages, and the minimum monthly fee just to sign up is expensive if you're only expecting a modest number of customers in the early days. They do have some serious limitations in their fraud protection that make us wary of chargebacks, such as not supporting 3D Secure and the liability shifting that should go with it.
We've considered numerous other options, including most of the ones mentioned in the article, but ruled everyone else out so far.
PayPal is a non-starter due the fact that on their new web site it seems you can't even look up basic details without signing up for an account and all that goes with doing so. Combine that with a well-documented history of poor customer service and some dubious terms last time we checked, and for us they're not a serious contender. The one thing you can see before signing up is the fees, which are high even before all the nasty extra percentages they can add on if you look carefully enough.
Paymill should be a much better option, but I simply couldn't understand their legal terms, so they've rule themselves out immediately. If they want companies like us to look at them, they need to hire a lawyer who speaks English, and then they need to write terms that are clear enough that we could confidently accept them without paying a small fortune for a lawyer to review them in detail. The Rocket relationship doesn't inspire confidence about them as a long-term partner for such a critical business function either, though that could be overcome.
We did consider a couple of traditional payment gateway + merchant account set-ups, and actually there seem to be some quite decent payment gateways these days in terms of service, fees and integration options. However, the heavyweight merchant account guys seem to be so risk averse and offer such absurd charges and waiting periods that we're not going to waste our time applying and sitting around for a month or more for an answer in case they deign to work with us.
As an extra data point, we also considered outsourcing the entire payment collection process to FastSpring. They were expensive and their system didn't seem to have a lot of flexibility, though in return they did seem to offer to do a lot of the set-up work we would otherwise need to do ourselves. The deal-breaker here was that we got the feeling they didn't really understand the tax and data protection rules in Europe and that gave us little confidence that their system would cope with our statutory obligations. This was quite a while ago, though, so perhaps they've improved more recently, and in any case they might be a better fit for people with a different business model.
Bottom line: For us, GoCardless is a clear first choice, and then once we're up and running we'll look at applying for Braintree to broaden our reach, as they want to see a bunch of stuff when you apply that we'll have done anyway by then.