Putting my bias of the maggie aside, of the three PD super chargers vendors (Edel, Whipple, Mag)...I hear you
the maggie kit ranks as a Napa parts bin closeout...it really does suck. The maggie kit I bought from Arrington back in May 2017 "was" complete and shipped from Magnuson directly. HOWEVER, the problem with the kit was complete for a 2009-2010 model...I had a 2015. The snout was too short, the fuse tap was the wrong type, there was no short IAT sensor (you were supposed to used the one that came with the car but the newer year challengers came stock with the long one) and the pulley was for a 6lb kit not 8lb. Once I got all the correct parts (Arrington did get everything addressed promptly even though they were in the midst of a change in ownership) assembly was a breeze. Did everything myself except for mounting the blower on the block (too heavy for one guy with no cherry picker) and did not have to take the front clip off. The injector size also depended on whether you bought the 6 or 8 lb kit. Oh and by the way the belt size was wack...I think they had the belt sizes reversed or something along those lines. Other than this fecal show (apparently this still happens to the +2015 guys that buy the self install kits) the maggie has performed flawlessly (did get belt squeal but the thump racing tensioner and correct belt size fixed that).
On thing to note is the Edel and Mag kits use similar Eaton blower design but the new Edel kits run a larger blower 2.65L as opposed to the 2.3L and have a larger intercooler...again bigger blower.
So taking all this into consideration I would rank the PD super charger pecking order in terms of performance and fit/finish for the DIYer as:
Whipple 2.9L (may require hood notch)
Edelbrock 2.65L (does not require hood notch)
Magnuson 2.3L (does not require hood notch)
That said the Maggie has done well by me and I have come to forgive the short comings of the kit (the shorter snout just pissed me off...I mean how do you miss that?!). I would have gone with the whipple but it was price (was ~$1.5k more for the whipple and it used a boost-a-pump instead of a larger fuel pump that API offered) and quietness (my rear diff whined enough) of the SC unit that made me buy the maggie. Also at the time of purchase the 2.65 Eaton did not exist yet and Edelbrock only offered a 6lb kit, hence no need for different injectors. That and there were a lot more folks running the maggie kits with no issues. Meanwhile the whipple guys were complaining of the light switch effect throttle. Nowadays I would say this is a moot point as the tunes and tuners have gotten better. Heck I think all PD super chargers were running a little orifice that would delay boost to prevent instant boost and boost during PT...that is no longer needed as the tune can address this...just ask the guys on the HP tuner site.
As for the maggie 8lb kit I bought, I paid $7200 out the door (no tax/shipping). It came with:
Trinity Tuner -- (I wish they used HP tuners instead but the trinity makes logging a breeze)
Tuning support -- (typically turn around was ~2days)
Magnuson PD kit with 60# injectors -- (API supplied the short IAT sensor and their upgraded SC idlers)
Crank pin kit -- (also bought a short 90 deg pneumatic drill shortest from HF)
API's fuel pump upgrade -- (bought the ring lock tool instead of using a brass punch and hammer)
This was everything that I needed to get the system installed and tuned. Install took only a total of 2 days but it took an extra month to get the right pulley, snout and tune dialed in.
Just another data point for you folks thinking of going forced induction.