i don’t have much experiance either way.
I assume with bush cherries you mean Prunus cerasus - Wikipedia ?
In the EU we call those sour cherries. Opposed to sweet cherries P. Avium.
I am however looking for the german varietie spinell
states it’s fruit weight 9.1g size 26.5mm 17.6% brix. 12.7 gram/liter malic acid.
Comes reasonable close to burlat (from the same paper) 8.9g 26.3mm 16.6 brix and 8.2 g/l malic acid.
Size weight brix etc are reasonable similair. Still a 1/3th difference in acid.
I think it also depends a lot on growing cirumstances. So it might not be a fair comparision or work out this way every year.
It is however comparing a sour cherry to a sweet cherry. So quite impressive.
This document lists similair attributes for spinell.
https://www.julius-kuehn.de/ex_anwendung/downloadFatPdf.php?file=2013_0098.pdf
It however does not list sweet cherry’s. So is harder to compare from.
This paper from 2017 (more recent) Also lists spinell as the sweetest/lowest acid sour cherry tested.
if you can’t read the papers. Read the scientific part of this topic.
Spinel also apeared to be quite monila resistant.
i also came across this presentation.
https://www.bordeaux.inra.fr/cherry/docs/dossiers/Activities/Meetings/2014%2009%2015-17%20WG1%20Meeting_Novi%20Sad/Presentations/Schuster_Novi-Sad2014.pdf
Have not had time to search for the papers that that presentation is based upon. (i assume they exsist from the same german institute)