It's rather cute how every LCG has a very loyal community that wants you to play their game. I have a friend who loves the LOTR LCG (he's also a Tolkien fanatic), but I'd never see him playing any of the others. He's convinced me to try playing it with him sometime...it is pretty neat that it's a co-op game.
I didn't know the Star Wars LCG had this "block deckbuilding". Do decks in that game not have a lot of different cards, or are the decks huge?
When you build a deck you build by taking objective sets. Each set is one objective card, and 5 regular play cards. They are themed and you have to put them in the deck as a set. When you build a deck for standard play you have to have a minimum of 10 objective sets in a deck. The objective cards are all put aside in an objective deck and these are revealed three at a time to play, and are what you basically fight over. This is part of how the game tries to keep the card themes to be thematic as while you for example are fighting a battle of hoth objective, you will for sure have hoth related cards to that objective in that deck. So at minimum you will have the 10 card objective deck, and then the remaining 50 play cards, though you can add as many objective sets you want in a deck, it's just not optimal build.
The starter comes with 4 premade decks out of the 6 factions, they are small decks of about 7-8 objective sets each I believe, but the starter does come with extras and neutrals that can be mixed in to make legal decks if you wish to play beyond the starter sized games. The Edge of Darkness expansion added 2 more prebuilt decks for the last two factions.
I play quite a few card games, like LOTR, Warhammer, and Star Wars, but because of that I'm trying to not take on anymore LCG's so i've not touched Netrunner.