I think Flare deserves a second look now that Data and Destiny has been released. I mean, we only got, what, less than 2 years before it's cycled out? Now is the time for Flare to shine (see what I did there?).

By itself, Flare rezzes at a whopping 9, so you wouldn't rez it unless you were darn sure you could land the trace and trash runner cards with reckless abandon. Aside from silly combos like Amazon Industrial Zone, I don't think you're going to find a cheaper way to rez this sucker (comment to prove me wrong). Therefore, you would look to combo with cards that make Flare even more powerful to get the most of that 9 punch to your wallet.

Ahem:

• NBN: Making News obviously improves your traces, but Improved Tracers does even more so. One ImpTrace in NBN:MN makes Flare a STR 7 with a Trace base str of 9. Holy cow. Maybe only Sunny is not blinded by that light (see what I did again there?).
• Any deck could use Primary Transmission Dish and/or Rutherford Grid to boost the trace.
• Surveillance Sweep is interesting here, as it forces the runner to pay money to equal 6 more than your current credit pool or suffer the consequences. Even if the trace doesn't land, the runner could potentially be broke. Wouldn't that suck if there was anything else in the server behind Flare that they would need money for?
• The Cleaners increases the meat damage to 3, so I can see Flare finding a home in Weyland.
• If you really want to get some replay out of Flare, surprise the runner with a Marcus Batty.

As far as taxing goes, this will probably cost the runner around 5 or 6 to get through consistently. Either they run through it with a credit lead on you and beat the trace, or they use Faerie, Garrote, or GS Shrike M2 to break the sub. Mimic needs 2-3 SuckerEyes counters, which is a bit painful. More than likely, the runner will avoid that server or use things like Inside Job or Femme to bypass.

Adam would click twice to get through from turn 1, and Sunny Lebeau: Security Specialist has enough link that you probably would never even install it in those match-ups.

Overall, I think you still need to build a synergistic deck around Flare to include it. There are more synergies out now to power it up and make it more worth the rez cost. Occasionally it may be a dead draw if you're broke or against certain match-ups. It is by no means a common include, but I hope to see a couple at tournaments in the next few years.

Flare, the card I would argue has the single most destructive subroutine in the game, however are you going to be able to trigger it?

Clocking it in at Nine credits and six Strength Flare can be broken for an average of 6.18 credits (That includes all breakers including Gingerbread) and out traced, this makes it very easy to get around (or even bypassed for one credit with Femme)

Comparing this to Uroboros a very similar in faction Tracer Sentry that costs Six credits and is broken on average for 5.3 credits (bypassing for two with femme) this doesn't seem like a very good deal.

While tracer ice directly benefit, from NBN making news, Primary Transmission Dish and Sub boost (which adds a solid end the run to it) it still overall lacks the push it needs to get a foothold in this game, it may be best to leave Flare as a one of copy in your Making news deck.

If the sub fires, you're going to get a pretty strong effect - Flare is one of only 2 pieces of ICE that deals meat damage and Flare's meat damage is unpreventable (+ it ETRs). However, that's a big If and without an on-encounter effect like other high-rez NBN ICE Data Raven, Tollbooth, Data Loop, Data Ward, Thoth, IP Block, the 9 investment just isn't worth it, especially if it's only going to get broken for 1 by Mimic and 3 Datasucker tokens.