The first fins I bought after becoming certified were the Platinas. For the money, they were pretty good in my opinion. For quick bursts of speeds, the dual blades worked really well with a small flutter kick, but my dive buddy was using jet fins (very similar to the Rocket fins) and I was always doing the flutter kick to try to keep up with him. The problem with jet or rocket fins is that they can cause major leg cramps if your legs are not strong enough to deal with them (ankles have to be really strong). Yeah, after a few weeks of constant diving you can build your legs up, but you might be hating life for a while (tried them...hated life!!)
You may want to look at some of the split fins. I have the Scubapro Twin Jets, but they pretty much work on the same principle. Some people prefer the stiffer Atomics to the twin jets...I haven't tried them so I can't say. After I tried the Twin Jets (ok...took me a few dives to get used to them..but since I was used to the flutter kick, I didn't take long) my Platinas stayed in the trunk of my car until our shop did a equipment charity drive for the local high school.
The split fins cost a little more..but if you find a pair you are happy with (at it may take a few dives) you will probably never need to upgrade again. TwinJets are guarenteed for life..if the blades ever rip or tear, they will be replaced if you bought them from an authorized dealer. Its well worth the money.
Hope this helps.