Hi Astrid @AstridHandbikebee63
I couldn’t wait so back before the PentaHarp was available in Germany I ordered the same thing from the Seydel Custom Shop: mine is built identical to the 1847 CLASSIC (maple comb, stainless steel reeds) and is in the key of Gm (which I decided on because that gives me Bb in the sweet 10th position on the PentaHarp – and that is the position that I think is the best on a PentaHarp because the “important” notes are all bendable, and my jazz buddies like playing in Bb).
I guess you forgot about this post about the PentaHarp that I wrote to you back in Nov. 2021 
Anyone interested in the PentaHarp tuning should refer to that post and then sit down with a sheet of paper and write out what scales/notes they can play with a particular PentaHarp key (which I presented in that post for the Gm PentaHarp).
Then I thought I would compare that to the Hohner PentaHarp and bought one in Am (which I would suggest you buy because A minor is something that guitarists find easy to play and many songs are in Am too – then that sweet 10th position lets you play songs that use the C scales too).
My personal preference is … impossible to say! I find both the Seydel and the Hohner harps to be great for playing things that you simply can’t do on a standard Richter tuned blues harp.
Regards,
– Slim 