I've been in the SUMAQ lounge (for free as AA elite) a couple of times, and it is nice. While I haven't been in the cheaper lounge, I will say that the SUMAQ was OK, and on a par with some international ACs. I would rate it a cut below AA FLs in terms of offerings, although it is more spacious than ORD, for example. It is nice, and better than the terminal, but not really anything special. The OJ machines are cool, though.
Cheers.
I was going to post about the OJ machine too - you beat me to it.
When I was in the Sumaq Lounge last month, I asked about access with Diners Club card and they said no. I donīt know if this is new or incorrect as Im sure the Diners Club website lists Lima airport as one with lounge access.