I've been using home studio 6 for several years. I'm familiar with it but I assume Sonar X3 will have a lot of things Home Studio doesnt. Has anyone else ever done this drastic of an upgrade? How was the learning curve?
 
I also use EZ Mix and EZ Drummer plug ins. Not EZ Mix 2 or 3, not EZ Drummer 2... just the first versions. Will these work in X3 or will I have to buy all new versions of those?
 
any help would be appreciated.

I loved SHS6XL and still have it installed on my Vista laptop.
A lot of X3 will be familiar, but many controls and setting are in different places now. This is probably the most difficult aspect to get used to. The learning curve is not nearly as fierce as learning SHS6 in the first place.
I would go with at least X3 Studio to make it worthwhile.
Do you have a lot of 32 bit plug-ins?
I do, so I am running the 32 bit version of X3 Studio. The 64 bit version is fine, if you stick with 64 bit plug-ins. Bit Bridge can be a little flaky.
EZ Drummer has been ported to 64 bit, so you would not need to buy a new version. You'll have to check on EZmix, but it probably has been ported as well.
What is your OS? X3 will run in Vista, although it is not supported. W7 or W8 is definitely better.
If you do a lot of work in PRV, you will really like the smart tool.
You might want to consider getting one of the X3 videos to help ease the transition.
All in all, I think you'll like it.
When I open SHS6 now, it seems kind of clunky and dated.
Good luck.

We actually did that upgrade not too long ago. While you will find that there are a lot of new things with Sonar X3, there is a lot that is still familiar for users of Home Studio. Many of the same basic functions work in Sonar as they did in Home Studio. There are a lot of new plug-ins, and Melodyne alone is worth the upgrade. 
 
As far as EZMix, can't help there. When I upgraded to Producer it came with Addictive Drums which is pretty nice and a nice step up from the Session Drummer in Home Studio.
 
Overall, if you do the upgrade you won't find it hard to adjust. Just a lot of new toys to play with, but the playing field will seem very familiar.

thanks to all of you, I might get the upgrade if the price is right. 
 
If I hate it I suppose I can always go back to HS6.... hopefully I can find a bunch of video tutorials and things like that to help me.
 
Home Studio is working fine for me, I just wondered if I'm missing out. Isnt Melodyne a sort of auto-tuner pitch correction thing? That would be nice.
 
I'll probably just run it in 32 bit to be safe with my old plug ins... what are the advantages of running it in 64? Faster? 

I'm running Windows 7 with the i-7 processor, its a powerful machine.
 
This would still be only to mix with, as recording is done via my XP machine and the M-Audio card.
 
the Windows 7 machine has a small little soundblaster card in it, its decent, I have to use ASIO 4 ALL to get it to show up in the Home Studio 6, I hope that works in SONAR X3
 
I dont want to get into the dreaded situation you all might be familair with.. upgrade one thing and suddenly half your other stuff doesnt work and you've got to do a bunch of purchases to upgrade it all
 
for example I dont want to have to buy a new soundcard for the windows 7 machine
 

As everyone else has said, Cakewalk retains the basic layout and terminology so a lot of features remain the same. There are some big changes to editing and a lot more features that takes the longest to understand. If this is the same computer that still runs HS 6 do not un install it. This gives you the option of using it it still, It will also allow X3 to port over your preferences and most of the old plug ins will show in the X3 list. I also recommend Studio as the best bang for the buck. 

The biggest difference is access to more RAM, if it is there. My computer only has 4Gb, so that advantage is moot. I have both versions installed, but the 32 bit is more stable on my particular machine. Rock solid, actually. ymmv.
Be sure to update to X3e.

Give the x3 demo a go you get a month to trial it. Should answer all your questions

Wrongnoterod
...Has anyone else ever done this drastic of an upgrade? How was the learning curve?...

 
I jumped from Sonar 7 to Sonar X2. It took me a few months to get fully adjusted to the new interface. A lot of functions that I was already familiar with seemed to be missing, but they weren't really missing, they were just accessed differently. It was confusing at first but well worth the trouble.

I'm still using SHS 6 XL even though I bought X3 during one of Cakewalk's sales last year. I'm not quite ready to start learning the new way.