Quoted from CrazyLevi:

Frontier is on the average to boring side for me, it's just another "light spinner, shoot the spinner, shoot the inline drops" Bally game of which there are a million. I never really get the cult around it when there's so many other Bally games just like it that have better art and themes.
If you are going for a game with that "wow" factor - which it looks like you are into with your collection - Frontier isn't going to provide that, while Fathom certainly will. There's a reason people pay the big money for Fathom.
If you are looking cheaper how about Skateball? That's a really fun game to play, super cool art, and different than the usual Bally fare (I mean kind of. Four flippers!). It's got a nice fast layout that was stolen from Flash with some magic added.
Another option would be Stern's Ali or Stars, both great games to play with a cool factor to them.

Quoted from sunnRAT:

Warlok's layout is identical to Blackout. Does it have interesting rules or improve on anything or is the main appeal it's rarity?