This BP is 4 pages long, 1 page front cover, 1 page SRD, leaving us with two pages of content, so let's check this out!
-Arcane Badge: As a first action in a round, change as a free action to a different type of bardic performance.
-Arcane Cadenza: Expend bardic spell slots to improve your performance you have running, extending it by an amount equal to the spell-slot expended without the thus powered performance counting against your daily limit. I don't like this feat. While powering bardic performances via spells sounds like a viable idea, its 1-on-1-ratio is not to my liking, mainly due to e.g. some bardic feats released use bardic performance-rounds much like a pool and thus, synergy between the two can't be guaranteed. Furthermore, the resource of bardic performances is essentially vastly expanded, making it less valuable. This feat won't see use in my campaign.
-Eldritch Arrangement: expend 1+ spell level rounds of bardic performance to make a perform check of DC 15 + 2xspell level to increase a spell as if widened, extended, enlarged or empowered (but all with reduced effect). Not a fan of this more versatile, yet weaker and rather complex feat - mechanics-wise, this one feels a bit cluttered.
-Extemporize: As a DC 15+ double modified spell level + number of feats added, reduce the casting time of a metamagic-affected spell to its regular casting time. Lose the spell on a failed check. Ok feat, though not one that gets me overly excited.
-Performance Focus: Treat your level as 4 levels higher when using a specified bardic performance.
-Transcendent Mind: Make perform-check instead of concentration-checks when casting bard spells.
-Virtuoso: Gain 1+ 1/3 bard level virtuoso points to either gain +5 to a single perform check, begin a bardic performance as faster actions (first move action, later swift or even as a free or immediate action) or ignore the chance to fail when using a performance with visual components or when deaf for a duration of Cha-bonus rounds.
Editing and formatting are top-notch, I didn't notice any glitches. Layout adheres to SGG's 3-column standard and the pdf has no bookmarks, but at this length needs none. The feats herein, while nice, are not for everyone. The aforementioned problem stemming from Arcane Cadenza with bardic performances as a pooled resource and the devaluation of these rounds by eliminating the difficulty of choice via providing essentially a vast array of rounds and supreme flexibility via arcane cadence. When I have the choice, I rather have the pool-approach to Bardic Feats pioneered in RiP's 101 Bardic Feats, which also provides the better bang-for-buck-ratio. All in all, while not essentially a bad pdf, the feats herein feel, at least to me, slightly less refined than usual for SGG - the mechanics for Eldritch Arrangement and Extemporize feeling not that streamlined to me. Aforementioned incompatibility also means this is much less useful for me than usual and thus, I feel I have to settle on "only" a final verdict of 3.5 stars - 3 if you're like me and don't like aforementioned incompatibility, 4 if you don't mind.