Hi,
I would not use (nor do I) Music Maker 15. It's problematic, buggy and they refuse to fix several problems. Many people get lucky and it works fine but as these post show many have problems with 15 that have carried forward from previous versions.

Until you're forced to change because you product is not compatible with your OS or until Magix fixes several problems there is no real reason to upgrade.

You can always get more Soundpool collections for more sounds
Justin

Here is my 2 cents.  I've been using MM 14pe and it's performed well for myself and my son, who likes the soundpools and all of that.

I checked out MM15 and then I checked out Samplitude Music Studio 15.  Both have free trial versions.  I decided to go with Music Studio 15 because the interface conforms more to other standard and professional music programs I've seen. 

I prefer to play my electric guitar through my effects boxes, into my amp and then into my PC using a regular microphone sitting in front of the amp speaker.  Old fasioned, I know, but it's still the best way to get real overdrive/distortion that doesn't sound all digitally compressed.

Music Studio gets the job done.  Also, using MM14, after recording a track, I always had to move the track back a little bit to sync up the sound.  That doesn't happen with Music Studio.

I don't do any midi recording, but from what I understand, Music Studio has the edge in that department, too.

Music Maker is a fine program, but Music Studio is a better tool for heading into the serious amature/professional recording direction.

Unless you like to do the soundpool music creation.  In that case, MM is the best solution.  Also, I believe you can put a video into MM and create your music track.  I'm not sure if that is possible in Music Studio.

So, basically, my advice is to install the free trial versions of both products and see how you like it.  To keep my PC clean, I've installed the free VMWare product and I install all trial software in my VMWare virtual PC.

Good luck.
 

VMWare virtual PC... is that an external hard drive?  I've not heard of that.

Thanks to everyone for responses.  I still want more input, as I check out all your ideas.  Again, thanks.

Samplitude Music Studio 14 is the best. I still use Music Maker 14 when i'm using external soundpools because its so easy and fast to cut and paste different samples and stuff from my VST Program. But for everything else; When I plug in my Guitar and Bass, or MIDI recording or basicly when you want a really high quality recording its gotta be Samplitude all the way. Even when I went into a music store and asked around they said Samplitude is in the top 3.