The old "Do you like T5?" poll is probably out of date, now that people are familiar with it and use it to some degree.
Here's a replacement poll. I think it should go without saying that it has my bias baked in, but there you go.
I can't see the poll!
I agree. The rough equivalent of The Traveller/Mongoose/Cepheus Book fills the big missing piece.I use T5 mainly as a supplement to MgT, but I use it a lot. It's interesting that the responses seem to skew toward the solitary game/support other game activities and that the two core mechanics used in at-table play -- tasks and combat -- are fairly low.
I think this highlights the need for the Player's Guide: if you're going to run a game, you really need to provide a convenient point of entry for players. Book 1 probably ain't that.