Christian Flor's chorale preludes represent the North German tradition of decorative hymn-based writing. It is distinguished by its ornate melodic lines that weave around the hymn melody.
At Henle 5 this is a late-intermediate piece — technically substantial, with musical demands to match. The main demands: independent voices that must each sing on their own line; ornaments that need to sound effortless, not squeezed in; and precise articulation — the difference between crisp and blurred is the piece.
The main difficulty is integrating ornaments naturally into the flowing contrapuntal lines.
Comparable difficulty and character — good candidates for what to learn next.
A level or two down with the same spirit — ideal if this piece is still out of reach.
Where this piece's skills lead: slightly harder works making similar technical demands.
Chorale Prelude is rated Henle level 5 of 9 — late intermediate repertoire, roughly ABRSM grades 6–7. In the RCM system it corresponds to about level 7.
You should be comfortable at Henle level 5 — meaning you can already play level 4–5 pieces cleanly. Learning it one level early is possible as a stretch piece, but more than that usually leads to months of frustration.
A typical performance of Chorale Prelude lasts about 3 minutes.
Chorale Prelude is available as free public-domain sheet music on IMSLP — the score is linked directly from this page.
Pieces at a comparable difficulty and character include 12 Variations in B-flat major by Wolfgang Amadeus Mozart, Intermezzo in A major, No. 2 by Johannes Brahms, Ave Maria d'Arcadelt by Franz Liszt — see the full similar-pieces list on this page.