"Total instruments" refers to the number of instrument plug-ins bundled with the product, not the number of instrument plug-ins supported in a project. For track/project limits see the General section at the top of http://www.cakewalk.com/Documentation?product=SONAR&language=3&help=Comparison.html
 
 
There is an error in the bundled instruments section for SONAR Home Studio. This product includes 6 instrument plug-ins: TTS-1, Studio Instruments Suite (Guitar, Drums, Piano and Strings), and Rapture Session.
 

Ok. So can I use more then 5 plug-ins and more then 5 vst midi tracks in Sonar Home studio? In Sonar LE I was using a 16 midi trakcs project, so I thought I could actually run up to 16 vst midi tracks in the same project. I never thought it could be a program limitation.

To use all 16 MIDI tracks in LE or the 128 in Home Studio would require using a multitimbral synth plug-in or an external module. For example, TTS-1 has 16 inputs and 4 outputs.  One TTS-1 instance could max out the MIDI track count in LE. Eight instances which is the maximum number of instruments per-project in Home Studio also maxes out the MIDI track count.

scook
"Total instruments" refers to the number of instrument plug-ins bundled with the product, not the number of instrument plug-ins supported in a project. For track/project limits see the General section at the top of http://www.cakewalk.com/Documentation?product=SONAR&language=3&help=Comparison.html
 
There is an error in the bundled instruments section for SONAR Home Studio. This product includes 6 instrument plug-ins: TTS-1, Studio Instruments Suite (Guitar, Drums, Piano and Strings), and Rapture Session.
 

According to that comparison, Home Studio is limited to 8 instruments, where Artist and above are unlimited.

But, if I uderstood well, I can use those 8 instruments for all 16 midi tracks, right?

-francesco-
But, if I uderstood well, I can use those 8 instruments for all 16 midi tracks, right?

Yes, I believe that should be correct.  You get 8 instrument instances to work with, but can have up to 128 MIDI tracks.
 
This could be useful for example, with the multi-timbral GM synth Cakewalk TTS-1.  You can route 16 separate MIDI tracks to one instrument, by sending each track to a different MIDI channel 1-16, with a different sound assigned on each channel in TTS-1.
 
There are other multi-timbral samplers which you could use this method with as well, such as NI Kontakt, Steinberg Halcion, or IK Sampletank.
 
Most other VST instruments can only play one sound at a time.  There may be some exceptions, such as AIR Xpand!2, which plays up to four parts on four channels.  This can be found on sale for as cheap as $1, and comes with 2500+ presets covering most instruments
https://www.audiodeluxe.com/products/virtual-instruments/air-xpand2

Thank you very much! So; is there any difference between buying Sonar Home/Artist from 0 or from upgrading Sonar LE? Do I have the same prices and procedures or does it change anything between the two situations?

I am not sure if LE qualifies for a discount. The store computes prices based on the products in your account. To see the actual price for a version of SONAR clicking the "Buy Now" button. The store will apply any discount due based on the contents of your account. Remove the unwanted product(s) from the cart. After performing this exercise, the store usually shows the adjusted prices in the catalog pages.

It it the same price so no discount I guess
Anyway...by installing one of them I will simply stop having Sonar LE and will start to have Sonar Premium / Artist instead, right?

You will have both. Cakewalk installs each version of SONAR in its own directory, however; all versions share some utilities and plug-ins. 32bit versions share one set of utilities, 64bit share another. If you do not want LE installed after installing a new version, consider deleting it before installing the newer version.