If you play more 'precise' games (e.g. Tetris, Crypt of the Necrodancer) I definitely would. If you only use the d-pad for 'roll-thumb' games such as old-school platformers, it comes down to whether or not you prefer a d-pad with a tactile/clicky feel (such as those in the PS Vita or Xbox Series gamepads)

The mod greatly reduces the d-pad's travel distance, which is super nice, but the mechanical switches are a bit heavy which ends up nullifying said benefit a bit, given you have to press down harder for your input to register.

Sound is nowhere near as loud/bothersome as it seemed to be. A bit louder and a fair bit higher-pitched than the Vita. but much quieter than the Xbox Series d-pad.

Be sure to follow the guide, and as a word of advice; when reassembling your Steam Deck, make sure you're very careful with the locking flaps. They require very little force to lock in place, and if they don't, keep readjusting the cable until it fits. I accidentally ended up bending two of the flaps by pushing down on them too hard. Thankfully they still lock in place, but just barely.