I have about one of each of the dots discussed. I used to have a FastFire II, but sold it because it was too hard to find the dot sometimes. The tube actually helps draw your eye right down the center, whereas the flat window without a tube can leave you searching for several seconds sometimes.
If you go with Primary Arms then make sure it is the new Advanced edition because those have the 10,000 hour battery life AND a lifetime warranty like Vortex. Holosun, and others make basically the same thing. The body, lenses and dot on the TRS-25 are basically the same as well, it is just 1/3rd the price, so a shorter battery life and not as solid attachments (perfect for a non-defense weapon like a 22LR in my opinion). The best value of all right now I think is the TruGlo micro dot, which is a rebranded Holosun for 2/3rd the price (just over $100), and it has the 10,000 hour battery life too, except no lifetime warranty (oh, and it has the auto on/off, unlike the PA one, which has a turret like the TRS-25)..
Here’s mine:
To summarize:
Bushnell TRA-25: ~$50+, Is proven to be rugged and hold true, as all of these are, no frills, 1yr warranty
TruGlo Tru-Tec 20mm: ~$120+, Auto on/off, 10k hour battery life, 1yr warranty (plus riser)
Primary Arms Advanced: ~$150+, Knob like Bushnell, Lifetime warranty (riser optional, I think)