In Sampletank iOS, there are multiple IAPs for different piano sounds...
... "SampleTank Additional Sounds" Piano Pack, 13 additional instruments
... "SampleTank Libraries" SampleTank PRO Classic Keys, 18 acoustic pianos
... "SampleTank Libraries" Sonik Synth, 7 acoustic pianos
... "SampleTank Libraries" Alan Parson Imperial Grand
... "SampleTank Libraries" Brandenburg Piano
... "SampleTank Libraries" Art Deco Piano
... "SampleTank Libraries" Miroslav Philharmonik 2 Piano
and then there are also a whole bunch more pianos you can buy in iGrand... a pack of 9 and a pack of 11 (of 22 total piano and related sounds) that can be added to the base set.
Most don't have in-app demos to listen to. (Even some that do don't play for me, for some reason.) How is one supposed to decide which to get? Are there online demos (of the iOS versions) somewhere? (Similarly, there are multiple packs of EPs, which I'd really like to hear.)
Related question: Are the iGrand pianos technically more advanced than the SampleTank pianos, or vice versa, or is there no pattern? (Same with iLectric vs the EPs in SampleTank.)