BrownieHey! They've had a trial for version 1 for years (as long as I've been using it) but idk if you mean trial for that or version 2. you can use the full features of version 1 for the first 31 days or something.
On another note, in the 7+ years I've been using Sai, they've only updated the program like once or twice. Fine with me, because it always worked fine, but I kinda thought that the developers had given up on it.
version 2 seems like a good start. they've added a gradient tool, text tool, shape tool, more layer modes, and more settings for brushed. all the things I like about version 1 still seem to be there, too.
what I mean by "good start" is that all of the new tools (gradient, text, shape, etc) are all extremely basic compared to their equivalents in larger programs such as photoshop and corel. like the shape tool has literally 3 shapes; rectangle, circle, and triangle.
the layer modes are really nice tho. i'm pretty sure they're about the same as the ones you can find in photoshop (sai only had about half in version 1), but I haven't checked yet.
i'm excited that they've added a ruler tool, including a straight and ellipse setting, and then a separate ruler tool that gives you 1, 2, and 3 vanishing point perspective rulers; and a 2 and 3 vanishing point perspective grid. I haven't tried using them in a real drawing yet, but they look like a really useful addition.
they've also added a layer mask tool, but i'm not entirely sure if it's working properly.
overall it's still a great program, but I would still suggest having a second program that has a larger selection of tools such as Photoshop, corel paint shop pro, or GIMP. though Sai has added things like text and shape tools, they still have a long way to go. it's really still just a digital painting/drawing program.
i'm excited for the future of it, though