All guitars in the Awaken tier are viable choices
I must disagree with the statement that a staff providing a 7% base M-ATK buff and Triple Hit DMG is not good for a class. That seems like an extreme exaggeration. It's important to consider that the Triple Hit DMG effect is only 25% less damage than the highly powerful sadness effect, which is arguably one of the most broken effects in the game. Regardless of how you evaluate the staff, there is no doubt that both the Awaken Angelic and Awaken Demonic staffs are the best options for an AE class. If you want to be a nuisance, go for Awaken Angelic; if you want to deal significant DPS, go for Awaken Demonic.
When it comes to the guitar, it's a different scenario, as all guitars in the Awaken tier are viable choices that ultimately depend on personal preference.
Awaken 100: Resistance Proc (10 points, not insignificant but not a huge amount), Double Hit Rate (2%), Decent base M-ATK buff, Decent M-ATK proc.
HoO: Magic DMG Dealt (an unmatched stat, compensates for any potential loss of base M-ATK), Movement Speed (not a significant amount), Nice debuff if you're not focused on dealing damage, and the buff side somewhat compensates for the lack of M-ATK.
Awaken 125: Triple Hit Rate (4%), Elemental DMG, Best base M-ATK buff, Decent M-ATK and Movement Speed proc.
Awaken 100: Lowest base M-ATK (results in less M-ATK from fortifications and gear upgrades), Limited to lower-level gems, No movement speed (whether this is a con or not depends on individual player preferences).
HoO: Likely lower overall M-ATK, No resistance drop proc.
Awaken 125: No resistance drop proc.
As someone who has played the game for a considerable time and engaged in PvP, here's my perspective:
While it may be disappointing to not have a resistance drop effect on the new guitar compared to the Awaken 100 version, it's essential to compare the +14 M-ATK on both weapons. Losing approximately 11.6k M-ATK is further compensated by KP points, achievement points, and various other M-ATK buffs, especially considering that the new weapon offers a 7% buff compared to 5%. All the lost M-ATK begins to add up, and the damage output is likely to be similar. Additionally, the new weapon provides an extra 25% damage on multi-hits, and the chance of triggering multi-hits is doubled.
Some might argue that using the Awaken 100 version allows for reducing Lightning Resistance for the Arch. While this is true, having more than one viable guitar option is a positive aspect, with cheap Eden Eternal Gold in Eden Eternal. There may be better ways to support the Arch, but if this is your preferred method, that's great.
Personally, if I were to build a bard, I would choose the new guitar. It has greater potential for upside and more possibilities with gems, future enhancements, and upgrades. Additionally, I find it visually appealing, which is a factor in this game.
I believe people tend to overestimate the power of resistance reduction, assuming that reducing the target's resistance automatically makes it the best option. However, without performing the necessary calculations and testing, I don't think this discussion should even be taking place.
Based on the discussions I've had about these weapons and Eden Eternal items, it seems that all of them have viability. I also don't think they completely overshadow previous weapons (although some might, but that could be an issue with the previous weapon rather than a problem with the new ones).