finally used the Union Medico Super Grip 90 needle guide! note I'll be referring to it as a needle guide, not an autoinjector – it's technically referred to as both by the manufacturer, but since you still have to manually press down the syringe's plunger, needle guide feels more accurate to me.

downsides:

it seems to keep about 1/8" of the needle outside the skin, which isn't an issue with the needles I'm using, but I could see being problematic if the needles you use are just long enough. I figured this was a non-issue, since I have 5/8" needles that work great at 45 degrees, so 90 degree and only ~1/2" of insertion seems fine. it was a bit fiddly to get the syringe into the device without touching the needle to anything, but I figured out a little trick: pull the needle guide plunger back, leave the cap on the injection needle, attach the syringe to the needle guide, release the needle guide plunger, remove the cap, and then pull the plunger back again. I did get a bit of bleeding after today's injection, but I think that's because I chose my injection site poorly, not the fault of the needle guide. I think next time I'm gonna try stretch the skin under the injector slightly before pressing the release button, which supposedly minimizes bleeding and leakage. I don't love that it only officially works with BD syringes, since generic brands like AHS and Exelor have syringes for 40-60^ cheaper than BD, but even BD syringes are only 50 cents apiece, or ~$26 for a year's supply (although I get 1ml BD Luer-Lock syringes free from my pharmacy, which is nice). I did get a pack of all the adaptors they sell, and plan to eventually order a few other syringe options and see if they can be fit into one of the existing syringe attachments.

upsides:

that was the least-painful needle insertion I have ever done or had done. I slide open the safety, pushed the button, and legit wondered if it had even gone in. but it did, and the rest of the injection went smoothly. removing the needle and the needle guide was a breeze – I opted to just pull the whole contraption out to pull the needle out, although you can pull the needle guide plunger back to keep the needle hidden from yourself until you dispose of it (I may try this out of curiosity next time, it just sounded like a finicky process today).

my overall thoughts:

• it's a bit fiddly to get the syringe and needle into the device, but I found a way to do so safely and easily.
• it does effectively reduce the length of your needles, so keep that in mind.
• it almost completely removes needle insertion pain, which was incredible.
• it effectively hides the needle from the use at the time of actual injection, although of course you'll still have to see it and deal with needles for draw-up and attaching the syringe to the needle guide.
• removal of the entire device in one go was easy, and I'll try the other removal method next week.
• it does only officially fit BD syringes, so keep that in mind (and you have to pick the syringe attachment you want at the time of ordering, or make a special request to get the other attachments included).