Josef Suk's early Op. 3 demonstrates a burgeoning Czech Romantic style that favors rich, song-like melodies and deep emotional expression. It serves as a strong example of his lyrical pianistic writing.
The challenge is to maintain the long, lyrical lines through sophisticated use of rubato and phrasing.
Comparable difficulty and character — good candidates for what to learn next.
Ballade and Serenade (Op.3) 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 Ballade and Serenade (Op.3) lasts about 6 minutes.
Ballade and Serenade (Op.3) 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 Am Rhein by Joachim Raff, Barcarolle by Anatoly Lyadov, Barcarolle by Anatoly Liadov — see the full similar-pieces list on this page.