I have a lot of experience with Lipoflame, but only started using Phenyl Core for a change of pace. There's no reason to run them together.
I haven't had enough time with Phenyl Core so I can't give you a detailed comparison, but both are good products. However, at this early stage I would still take Lipoflame over Phenyl Core. Plus Omega is a good bro, so Lipo would get the nod in a head-to-head race.
Both have great thermogenic properties, increase endurance, and provide an overall sense of well-being. Not being a coffee fan, this is my morning pick me up.
And definitely get Lipo if you're considering Amp since you can get them together. It will definitely improve your lean muscle gains.