The last review (from 2015) is good, but it is time to make an update (we're in late 2020), it will be very similar to the analysis of R&D Interface, since it does exactly the same effect, only on HQ instead of R&D.
To summarize it, HQ Interface (HQI) is good if you have the economy and you can make run cheaply.
Does not need for the run to be declared successful to work. Cards like Legwork can be foiled by Crisium Grid.
The more you run, the cheaper it get. For exemple, The Legwork let you see 3 cards for 2 credits, for one run Optimally, you'll be able to see 9 cards in 3 runs. For the same effect, you need 2 HQI (8 credits). After 4 runs on HQ, it is cheaper to have used HQI. With one HQI, you'll need to run 5 times, but you'll have spend 2 credits less than using Legwork.
It stay on the board, so you cannot lose that advantage with damage, making it more reliable. Losing the run to an Nisei MK II or Border Control does not lose you the card. You can run again and apply the pressure.
It synergize well with alternative ways to have multiaccess, because it add to it.
It synergize also well with tools to make run cheaply, because it makes those run more powerful. Bypass tools are great here, allowing the runner to access more than one card, while using their limited resources of bypass tools.
It is more expensive than any event card.
It is a tempo hit, because the card cost you a click to install and 4 creds, while an event card (Legwork for exemple) cost you creds and makes you run.
You need to be able to make run cheaply. If you can only do a couple of "big" runs, you'll be better off with alternatives.
Alternatives for Multiaccess.
The Turning Wheel. You can access an additional card every third run. Usually, you'll stack your counter to make a 5 cards multiaccess run.
Climactic Showdown. Can be foiled if the corp trash an ice.
Information Sifting, give the choice to the corp for which card goes in which pile. Successful run needed.
Wanton Destruction, cost you the full turn usually. Successful run needed.
The Gaunlet need you to break completely each ices and it is a console (you can only have one console).
Severnius Stim Implant. It cost you cards.
Mu Safecracker. You need stealth creds. Successful run needed.
Legwork. The main competition. Successful run needed.
Divide and Conquer. Access to all centrals at the same time. You need to access Archive first, which could be dangerous. Successful run needed.
The Black Hat. You need links and a credit lead to make it work, but otherwise top tier.
Bhagat. Indirect multiaccess of R&D when running HQ. Successful run needed.
At 2 influence, HQI can be splashed in any deck that can make runs cheap. Just putting it on the board will make the corp ice HQ more, freeing other place for you to run. If you have ways to install HQI for a lesser cost (with cards like Modded), it is even better.
The text if flavorful and on point. It explain the art of the card. That how things should be.