Actually, it does make a difference. Some apps for example are more efficient than others. In general, Logic is pretty efficient in resource usage, and DP for example is generally thought of as less efficient. Arturia and Spectrasnonics are not too demanding on an individual basis, and with NI depends. The more software instruments, the more taxing it is, at which point you need to limit your tracks, and the other way around. If you use a moderate amount of instruments, you can get up to quite a few tracks. Also depends on what you want to do - real time playback editing will obviously be more taxing, if you do it piecemeal, it'll be easier. Unless you are doing orchestral work though, you can pretty much work around any hardware limitations with the setup you're getting.