I don't mind that they went turn-based here, but I hear you about the length. I'm hoping this won't be quite as long as the Pathfinder games. I'm growing tired of every new RPG being 100+ hours long.
I have been more comfortable with TB of late - That recent King Arthur game with Mordred, Midnight Suns, and Wartales, being three examples of TB games I am enjoying.
I also enjoy very long games IF I really like them, i.e., like on my personal game rating a 9 or 10. I like to really sink into games I love. On the other hand I don't play a lot of games, and find few games I really love, so I have more time.
I love WOTR but if I had to play that all TB ... I honestly doubt I would have ever finished it. The battles just drag out so much.
Rogue Trader won't have any other option so if it is as long as WOTR, and I have less interest in the lore and setting, then I have trouble seeing myself enjoying it enough to finish. That being said I read that "trash mobs" act 3 at a time and maybe it speeds up the TB combat enough. I would still need to get excited over the setting, the companions, and the rest of the non-combat stuff though.
Speaking of custom parties vs. premade companions, I see both sides of this and both add content but it is not an equal exchange.
A game that comes with robust and in-depth companions to form your party will have a great deal of content related to them - relationships, quests, dialogue, lore, inter-actions, and so on. If you have the option to make your own full party from scratch (like you could in Kingmaker and WOTR) then you gain content as Purple pointed out - in that you can customize every thing about them, make your own back story for them in your head, and fully control them. So there is content there. But it is far less content. Even if the game lets you add some basic personality and background to them like Solasta, those custom made party members will never have the full extent of content that comes with the developers companions.
So you do in fact lose content, and you lose a great deal of it, if you make your own party but you also gain some content by doing so, just a whole lot less of it. For some that doesn't matter as they have little interest in relationships and companions and if they do want some of that they just make it up in their head. I have done that a few times. In Kingmaker I made my own partner to the main character. He had no quests or content like a premade but I knew his story in my head.
But from a purely in-game measurement (i.e. excluding what you RP in your head - as making up content in your head for these companions is not game content by any stretch of the imagination) you will lose a lot of the game content going with a custom party as custom made are usually pack-mules and meat shields and their small set of generic one liners, e.g., combat yell, selected, go there, etc. won't come close to replacing all the developer made content that comes with premades (depending on the game of course).
