sbm12 pretty much said it all, it depends on what information you want. For example, since you're a DL Platinum Medallion, you may find ExpertFlyer's DL upgrade inventory display (V,G,Z,X) useful, especially since it isn't available via any other website or tool, not even DL.com. (Same for AA upgrades.) You can then use Flight Alerts to let you know when any award/upgrade inventory that we support opens up, also unique to ExpertFlyer.

We also have award availability for AF and, as soon as our GDS fixes one of their bugs, KLM as well. We also have full information for UA. However we don't have awards for CO and US.

Either way, you have to try it all out and see what works for you. ExpertFlyer offers a 5-day no credit card free trial. KVS doesn't publish one on his website, but maybe he will give you one if you ask. Also on ExpertFlyer you can sign up for a month at a time and deactivate/reactivate your account as needed if you don't fly that often, no worries.

Let me know if you have any questions.