I'm not sure if this would be a step up or not and was hoping someone here who has far more knowledge than I, could point me in the right direction.   Since Music Creator 6 is dirt cheap now and more compatible with current plug ins, addon's, etc I was wondering if it was worthwhile to scrap using GTP3 in favor of it before I get much further into recording more music.
Even though I've had GTP3 for years I wasn't able to dedicate enough time to get into any in depth home recording, until recently (only have 2 songs finished and 3 more in the works).  So in a nutshell, I'm still pretty much a beginner, even though I've had the program for quite a while but only used it sporadically.  One of the reasons I'm considering a switch is due the lack of compatibility with various drum/instrument packages that are currently available. 
I have another computer set up just for home recording and realize that any switch would mean that there would be an OS and, most likely, a  hardware upgrade that would be needed also. 
Thank you in advance for any advice you can offer.
 

That's kind of a tough call. You would gain VST instrument support, which is huge. I believe GTP3 supported more inputs. If you are just recording yourself, that is not a big deal.
I'm going to throw another option at you.
As a registered customer, you can upgrade to X3 (basic version) for the same price as MC6. This would be a major step up for you, but your OS could be an issue. It won't run on XP. It will run on Vista, but some functions are a little flaky.
 I doubt if upgrading to Vista or W7 is still an option for you. It is extremely unlikely that a system designed to work with XP could be successfully upgraded to W8.
I really liked XP , but when my own XP machine died recently, I found myself at a crossroad similar to what you are looking at.
I have been shopping Newegg for refurbished W7/W8 machines and there are some very good deals.
If your budget will allow, you are at a prime spot to upgrade your whole system for dirt cheap.
Do you have an interface? Even with a newer computer, the built-in sound card will offer marginal performance.
If you do start to get into this, you will inevitably experience what we fondly refer to as GAS (Gear Acquisition Syndrome).
For a relatively modest outlay, you can build an environment that is a joy to record in.
If you do go with MC6(using your current OS), get the non-touch version. It is compatible with XP and Vista.
While it is not the most cost-effective solution, it is a viable option with your current hardware/OS.
I know this is a lot to chew on, but hopefully it will help you make an informed decision.

Thank you for your quick reply Robert. 
Right now I'm only recording myself, so losing extra inputs wouldn't affect anything that I'll be doing anytime soon.
I just realized that my signature had listed old info (now deleted) regarding the computer components in my recording computer.  To answer your question, the interface is a Line 6 Tone Port UX2 connected through USB with Asio drivers.  That computer has an intel E8600 Core 2 Duo CPU which has so far, served me well with what I've been able to do with my music files through GTP3.  And I agree, I really like XP also.  As for vst instrument support, that is exactly what I will need for what I want to do in the near future. I have been utilizing free backing tracks from the internet for my bass, drums, keys, etc and importing them to their own track in a new project then recording my guitar parts onto separate tracks to complete my recording.  This has worked pretty well so far, but eventually I want to create my own original music from the ground up and the enhanced vst support for instruments is what I'll need. 
Thank you also for your suggestion with regard to the X3 basic version too.  It looks as if I may follow that route instead of getting music creator.
Oh, and I have already been treated for G.A.S on several occasions, LOL.  From what you mentioned (and I agree) it sounds as if I'm going to be in for another outbreak soon.
Thanks again for your advice I really appreciate it.  You have been more than helpful.
Mark

Glad to help.
The UX2 is a decent unit. I think you will really enjoy working with VST instruments(soft synths). They have become a staple for me.
For creating your own stuff, I highly recommend looking into a MIDI keyboard controller. I wouldn't be without mine at this point.
This may not be your cup of tea, but just to whet your whistle, this tune is entirely VST instruments triggered live with a MIDI controller:
http://soundclick.com/share.cfm?id=10285834
I love this stuff.

WOW!  You see, that's what I'm talking about.  That sounded great.  It reminded me of something Yanni would produce.  I know there are some who don't care for his music, but I do, so I definitely meant that as a compliment.  Your other compositions were good as well and I really liked how they all had their own individual flavor and style.  I had seen that your musical influences were "all over the board" so to speak, and I can certainly identify with that as well.
Ok, ok, you've convinced me, now I have to add a MIDI controller to the list......hmmmm, maybe I can get Santa, err, I mean my wife to get me one for Christmas.
Thanks again.
Mark