As someone who has used both tools, I'd throw out the following:

Both tools have their strengths and weaknesses, and which one you use really depends on your current needs. I would not be surprised to learn that many people have subscriptions to both tools.


Likes with EF:

• Award availability for CA/FM/LX and more detailed availability on UA. When I was booking award tickets to China for the Olympics this summer, this was a huge help and timesaver.
• Saved flight alerts/email alerts.
• Fares and Routing Rules.
• Graphical seatmaps.

Dislikes with EF:

• I think it's kind of expensive for what you get.
• It's not as fast for me as KVS (possibly a browser/javascript issue).
• I think the banner ads are tacky and inappropriate considering I'm paying a monthly fee for this service, not to mention they really impact browsing from a mobile phone.

I haven't used KVS for over a year now, but at one time I had it installed at work and on my laptop and made frequent use of it (when I was using it there was no *A award availability checking).

Likes with KVS:

• Fast, easy to use with keyboard.
• Convenient award availability checking (this is assumed as I didn't get to experience it).
• Better overall value.

Dislikes with KVS:

• No configurable email alerts.
• No award inventory for CA/FM/LX.
• Sometimes seemed a little "clunky".

I honestly don't recall any details on printing from KVS - from EF, it's easy to do. EF can also search availability across a total of 7 days - this is very handy when planning award or MR travel - not sure how KVS compares. Finally, I'm not sure how the two compare for mobile usage - EF advertises a mobile homepage but I always forget the address when I'm traveling (dumb I know), and it's been too long for me to recall whether KVS had a WindowsCE version or not.

Frankly, the other thing that really helps a lot no matter which tool you use is a good understanding of how airfares/rules/routings work - with that knowledge, one or both of these tools, and extensive use of the ITASoftware website (free), you can really do amazing things when it comes to maximizing value on revenue or award travel.

Guess it's time to try KVS out again - would like to see how it compares to the ANA tool for award checking.