You likely won't notice much slowdown as you install applications because
Linux applications usually do not stay resident in memory and pre-load to
the system tray which is a practice many developers have fallen into under
Windows. It is not necessarily a fault of Windows that this happens but
Linux makes it harder for this to happen and open source developers are
more aware of these things. Most Windows performance degradation is related
to all of the necessary additions like anti-spyware and anti-virus that
check for updates and install them plus crapware from the OEM that seem to
need to run from the system tray. Then they ask you to re-boot
periodically. Also the Windows registry gets bigger and gets fragmented
over time. This can slow down applications starting up and running. Linux
has no registry.

I am glad that you like Ubuntu Studio. Try to support them as you can by
joining their community and donating time and/or money. This project is
worthy of support, but it is one of the smaller ones and it was on the
brink of failing not long ago. Of course, this is totally voluntary in open
source. This applies to all projects in Linux. But it encourages developers
even if you send a dollar or two. They add up and help pay for servers.
Nobody will get rich on donations to Linux. :)