Appearing Too Late
According to the current arrangement by Riot, Light items will appear in rounds 3-6 and will only show up once throughout the match. While some players may not have assembled items by this round, they have generally already formed their gameplay strategy and most carries have at least one item by then. Therefore, with the random mechanism, players may not have the opportunity to acquire the Light items they desire.
Take the case of Guinsoo’s Rageblade as an example. Its appearance in rounds 3-6 typically suits players who build their gameplay around champions costing 4 gold or more, which will show up later. However, if a player is focusing on champions like Irelia or Tristana, the late appearance of the Rageblade in rounds 3-6 feels rather too late, as players have almost decided on the items needed for these champions, and the final slot is often reserved for defensive items.

Only Appears Once Throughout the Match
Except for the Glove of Precision, players do not have any opportunity to acquire another Light item, so the choice must be very precise. However, with the randomness and the low odds of getting a Light item that fits their playstyle, lower-ranked players or newcomers will find it hard to adapt their strategy based on items, especially by rounds 3-6 when they must have already shaped their team and started upgrading.
All Light items in season 5.5 are strong in some way, and players must possess enough skill and luck to maximize the potential of these items. However, the fact that a Light item can only be chosen once sometimes forces players to reluctantly select items they have no idea how to utilize properly. If they don’t choose, they miss out, but if they do, there’s no chance to correct their mistake.

Benefits Provided by Items
Almost all Light items in season 5.5 provide significant bonus stats to their owners and all allies, but some items are merely upgrades that double the effects of their regular counterparts and only provide those stats to the owner, without any additional effects. For example, Hirana’s Spear restores 15 energy from each auto-attack for the owner (the regular version restores 8 energy), with no other changes.
As mentioned earlier, Light items appear in rounds 3-6, when most players have already defined their gameplay and necessary items. With an item crafted from B.F. Sword and Tear (two items that have a relatively high drop rate and are contested only moderately), players may have already assembled Spear of Shojin if they intended to play a magic damage-heavy team. Therefore, the appearance of Hirana’s Spear may be excessive in certain situations.

Of course, each item will have different aspects, and whether an item is strong or weak depends significantly on the gameplay that players build. With items that only drop once like Light items, players must calculate carefully and have contingency plans in place for when the items do not turn out as expected.