Good move, you'll be happy in the long run.  As noted in previous posts, you will probably have some frustrations early on -- there are some bugs that can be frustrating, but the biggest thing is the learning curve; functions are not always intuitive, but this forum was a life saver for me. 
 
It's just a "hobby" for me too, but it's so much fun it's hard to put it down.  I don't have the experience with other DAW's as some of the other respondents do, but started with 6.x bundled with an interface.  No major problems, but clearly X1d Expanded is an overall very stable and very functional product.  Best move I made was getting a dedicated computer; seemed like a big investment as a hobbyist, but made a huge difference in overal stability.

In my humble opinion, you've made a very good choice and one which will, despite the inevitable frustrations, bring you many years of FUN

If you haven't done so already, grab yourself a copy of Scott Garrigus's SONAR POWER X1 book and read it from cover to cover.

horrendous friction attributed to upgrading my hardware, e.g. yesterday I thought I'd recorded a bass guitar track, hearing my playing, seeing the waveform accumulate etc., but when I finished the recording, the waveform disappeared and I was left with an empty clip. Nothing made the recording reappear ... the day before, I had done exactly the same thing with a guitar track, that is still there!?!?! I can't say whether such erratically unpredictable behaviour is down to X1, Win7 64bit or my hardware (Cakewalk and Roland!!) or whatever, but I'm presently not a happy customer, given that my money showed none of the problems the merchandise is torturing me (and many other users - just count the forum posts) with. Still, if X1 were to run consistently well, I'm sure it would be the fun it's meant to be. So if you get it cheaply enough, it can be worth the effort - I wish you more luck than I've had.

If you're having major stability issues, have you tested the core hardware of your machine (RAM, etc) to be sure it's stable?  Looking at your specs, there's no good reason why X1d should be that unstable.

 Jim wrote: > If you're having major stability issues, have you tested the core
> hardware of your machine (RAM, etc) to be sure it's stable?
> Looking at your specs, there's no good reason why X1d should be that
>unstable.

Thanx for the hint - No, I haven't tested the hardware. I hope the problem doesn't lie there, as the shop I bought it from have turned out to be very unhelpful and unfriendly.
Some of the quirks I experienced with X1 haven't cropped up again yet, others seem to be genuine bugs, for which I suppose future patches will help. So I'm presently not as frustrated as when I posted recently. And when it works, I find X1 to be as much fun as I'd hoped.