I was pretty excited when the Surface Pro arrived about 10 days ago, so I could test it ahead of its release on Saturday.

Finally, a tablet that’s also a laptop that also runs a mature operating system — Windows 8 — and lets me use all the PC software I know and love. This is the machine I’ve been waiting for. After more than a week of using it, I appreciate its strengths but I’m less excited because I can see its warts along with its good points.

First the good stuff. It really is a full-blown Windows PC. Every program I tested it with worked out of the box. After using iPads, Android tablets, Chrome laptops and even Microsoft’s own Surface RT, it was a welcome relief to be able to install and use my favorite Windows programs.

I also like that it’s reasonably small and light. With the optional Type cover (that sort of turns into a laptop), it weighs 2.53 pounds — only slightly heavier than the 2.38 pound, 11-inch MacBook Air. I also like that it’s two devices in one. Windows Surface owners don’t have to carry around a separate tablet because their computer is their tablet and their tablet is their computer. It also has a great screen and comes with a digitizer pen that allows you to do precision work without giving up the ability to use your fingers as you would with an iPad or Android tablet.

I’ve grown to like Windows 8 on a touchscreen device like the Surface Pro. I am not a fan of Windows 8 for older machines that don’t have touchscreens, but it’s a great OS for touchscreen systems.

I also found that the machine is peppy and responsive in almost every way, but there is one “but” that I’ll get to in a moment.

The Surface Pro supports two optional keyboards from Microsoft that also act as covers. There is $119.99 “Touch” cover/keyboard which is really designed for people who don’t do much typing and there is the $129.99 Type cover that Microsoft bills as having “mechanical keys for rapid typing.”

Both keyboards are thin and light, but the Type keyboard has the same key spacing as a standard desktop and laptop keyboards. That came as a surprise to me for two reasons. First, because it looks smaller and second, because when I type on it, I find myself making more mistakes than I make with a full-size keyboard. I assumed it was about 10 percent smaller, but when I measured I found out it was the same size.

I’m not sure why this is happening, but I find that I can actually out-type the Touch keyboard. Yes, I’m a fast typist, but any computer should be able to keep up with any typist. To be clear, it was the keyboard and not the machine itself — I plugged in a desktop USB keyboard and it worked fine. I’m hoping that Microsoft improves the keyboard or third-party keyboards are made to deal with the problem.

The other issue thing that keeps Surface Pro from being a full laptop replacement is that the keyboard is not rigidly attached. The magnetic attachment works fine and there is a kickstand for the screen that lets you place it so it works like a laptop when you’re at a table or a desk.

However, it’s hard to use the Surface Pro as a literal laptop since the screen keeps flopping over if you hold it on your lap or you try to use it lying down (which I admit I sometimes do).

As a tablet, it works well, although at 2 pounds without a physical keyboard, it’s heavier than the 1.44 pound iPad. I like Microsoft’s onscreen keyboard and agree that the Windows 8 tiles interface works well for a touchscreen tablet.

While some people will be able to use the Surface Pro as a laptop replacement, I’m not one of them — at least until the resolve my keyboard issues. The Surface Pro starts at $899. For details, visit Surface.com.

Larry Magid’s technology column appears Wednesdays in The Daily News. Email him at larry@larrymagid.com.