Hi all, new to the forums so sorry if I ask any dumb/obvious questions

So I usually run Any% standard NG, and just recently discovered the existence of the repair kit under the house near the RV. The route I normally used had you go from Jack 2 to the recreation room to get the broken shotgun/blue dogs head->main hall to swap the broken shotgun for the normal shotgun and get the pendulum->Dining area to get the white dog's head.

Now I know we get the shotgun to save time on Marguerite, but I'm trying to determine which is faster: swapping the broken shotgun for the normal, or repairing the broken shotgun into the more powerful shotgun (but only holds 2 rounds). So far this is the list I've made:

Standard Shotgun (M37): -Holds 4 shots instead of 2, so needs to reload less -Comes with 4 rounds already in the chamber, so it's like getting 2 shells for free -Can avoid having to get the repair kit under the house (honestly, getting the repair kit takes about as much time as swapping one shotgun for the other, so not a terrible amount of time saved)

Repaired Shotgun (M21): -More powerful than the M37, can kill a standard/four legged molded in one shot or take out Jack's eyes in 2 shells each -Holds 2 rounds instead of 4, but has a faster reload animation and fires as fast as you can pull the trigger (useful for bosses) -Gives you two free inventory spaces since you don't need to swap shotguns -Routing for it is more efficient: you can go from Jack 2, get the pendulum->recreation room for the shotgun and blue dog->drop off the broken stairs to put you right at the dining hall. Saves a trip from the recreation room to the main hall to the dining area

In any case, I shaved a bit of time off my pb when I used it, but I could have just had a lucky run. I was wondering what everyone else's opinion on it was?