Now available for linux and android! I enjoy playing it on my android tablet...
You can order it for a cheap price with the current humble bundle.

I feel that avadon series is possible for each game to be played twice. I found that the story is good enough and because the game plays likewise with missions, it makes it much more playable than say jeff's other titles. Also keep in mind, each character can be played many different ways.

Take the blade master class, i took up a bow, pumped all my points into dex and endurance and used no battle attacks other than the arrow aoe attack and a few debuffs. You could go back and play the blade master the usual way of strength and dex as a melee fighter. You can do that for almost all the other characters in game. The shadow walker, shaman and sorceress can be made unique.

That is not easy to say for jeff's other work. The gene forge series, avernum series and any of the other games he's made I will only play through once. Its not because they aren't good games, but its because jeff changes very little between games. The gene forge series is one of my favorite games jeff made, but i have to admit that there's very little classes to be had after you play through a game. You play an agent and then play a guardian, the only choices you have for a character type is 1 each. Melee, ranged, shaping and magic and of course hybrids of each.

You don't have more than 1 choice to choose from in game. There's no anatomy like in first gene forge where you can focus on that instead of quick action. In reality, you play the same chars in all the games except the first.

To get to eschalon series, there's a large amount of replay ability in game.

-the games have massive worlds, with medium length main quest story lines, and a large amount of character types. If you play as a melee fighter in eschalon and then play as a ranger, its a completely different game. Just like in avadon where playing a shadow walker and then going to a sorc is completely different.

BW has a world that is unique. The next best thing would be that someday he decides to get a party based rpg in the eschalon world. That would be killer!

Geneforge games have replay value for the story lines. You pick whether you stay loyal to the Shapers or support a faction. Depending upon who you support you will only get certain quests and get dialog options.

Avernum games have less replay value unless you are into challenge games like all magic users, no magic, a single character or some other restriction.

Have played avadon some hours,would say half the game, but can´t shake the feeling that the worlds are somewhat " empty " , no offense.

Although i like the combat system and the story is surely interesting , it doesn´t give me the sensation of world.

If there´s something that the eschalon series has. ( apart from the other good things of course ), is the feeling that everything is put into it´s place naturally, and not with a "dropthatthinghere" editor.

I recall some post of BW , telling that he sometimes takes it´s time putting, moving or removing items from scenario or map ,until he finally gets it right,although having the feeling that we won´t see any difference, i would say that this actitude, is what makes this game as unique as it is.

I agree with almost everything you said. I find that there is no doubt that bw took more time making and mastering his worlds and you can see it. I still do find jeff's to be more my fancy, but to each his own. Still the solo experience you get in eschalon is epic.