I'm looking at the authorize.net application and it has listed on it all the merchant account processors - first data, nova, vital, global, ...

Is one payment processor better than the other - something like "X always gives us problems, but Y is has no issues at all".

It's not processors, it's a combination of a number of factors that come into play. Processor itself has no direct relationship to merchant, since between them you have in most cases acquiring bank who gives you MID, sales agent who services your account, and payment gateway.
If you want to know my opinion: stay away from Nova and Global, and stick to either First data, Vital (now TSYS), or Paymentech. Nova and Global are great platforms for traditional POS business, but you do not want to process e-commerce transactions with them.
Authorize.net has a lot of complaints lately, and they are IMHO not as cost-efficient as other gateways. We moved all our accounts from Auth.net to USAePAY.
Hope this helps.

All of the payment networks like First Data, Nova, Global, Vital are the same from a merchant's point of view. They're all reliable. They have to be. If they weren't they would be shut down in a heartbeat.

What you need to be concerned with is the company that establishes your account and handles your processing. They will vary in many respects in terms of cost, customer service, flexibility with your account, software supported and more. In your case they all support Authorize.Net so that isn't an issue. But the cost and overall experience will vary. That's why you should always shop around and ask lots of questions.

BTW, Nova and Global have absolutely no problems with ecommerce. We set up ecommerce accounts through them every day.

Stymiee, - AuthorizeNet Supports them all. Other way around.

Main thing about this case, is that First Data, Vital, and Paymentech are your 3 big ones of all 12 back end processors between the US and canada. Depending on if you change your business path or gateway in the future, you may have to change merchant accounts or backend processors. Not all MSPs can give you access to all front ends. Most Sell on First Data, 50% Can do Vital and Paymentech. But the others are more for specific banks. These 3 listed are the 3 biggest for online processing.

Bad Example, If you were a retail store with an older card swiper - Might only have access to Vital because they still support much older terminals for truncation. (Truncation = encoding CC data, especially on Receipts) But see you wont have that issue.

Related Example: Lets say you wanted to use USA E Pay, my favorite payment gateway. This gateway is pretty strict. They only accept FDR, Vital, and Paymentech. No others. So youd have to have one of these just to use that gateway. I was on CardSystems, I had to make a big change to Vital, because my MSP didnt support FDR or Paymentech. It was worth it, because UEP has way more functionality than the other gateways.

Ive worked my butt off making sure most shopping carts accept alternative gateways over the years, but some just didnt want to take the time to integrate. E-Processing Network is another favorite gateway of mine, because they have less "extra" fees than AuthorizeNet, and they have an Emulator, so people integrated with AuthNet already, only have to change their Post URL, Key, and ID. They also have free manual recurring payment setup, and lots more reporting details. And my biggest thing = cheaper.

Stymiee, - AuthorizeNet Supports them all. Other way around. Actually gateway and software providers (as well as terminals) have to be certified by the platforms. The gateway/software provider has to first make their product work with the platform's API and then they submit it for certification. Until it is certified it cannot be used with that platform.

That's definitely correct. It is the obligation of the 3rd party gateway, software vendor or terminal manufacturer to certify with each front-end that their product is designed to work with.

There are some differences between different front-ends. The Global front-end network, for instance, has has more statistical down time than most others. I have heard many horror stories from people in the industry who use that platform complaining about restaurants being unable to process on busy Friday nights and all kinds of other situations.

The Vital front-end network works well but the problem with that is that sometimes it can add an extra day's delay on the funding side based upon the way the front-end data is batch transmitted to the back-end in certain scenarios.

I personally prefer the Paymentech front-end network for a lot of reasons, one of which is reliability and the other reasons are more related to back office benefits that make support faster and more efficient.

Ultimately, any or all of these networks will do the same thing and generally get the same job done for any given merchant. There are some differences but in most cases they won't be noticeable to an end user.