No, it's a classic episode and I love those original three Klingon ships rather than the new CGI mob! Sub-Commander Tal looked pretty frightening I thought when he appears on screen and vicious enough to order the complete destruction of the Enterprise on a whim!

JB
I can definitely see why the original trio of Klingon ships worked better. Physical models tend to hold up better and those Klingon ship models were great for a 1960s TV show, much less its third season that was put to the backburner by the network. And the angles used for the f/x were largely excellent as well, the new model did get a fair amount of the budget and they found a clever way to use it. I recall Fontana's first draft having a bit more meat in the setup of a Romulan/Klingon alliance, whereas the produced episode glosses over that and arguably goes for the Cloaking Device
I don’t dislike this episode, but it does strain the credibility of Treknology, such as it is
Not disagreed. It does strain, but IMHO the timing and pacing of it all help soften the blow, wisely keeping the most of it until the end.
, almost to the breaking point:
1. The cloaking device is conveniently small and light enough to carry around like a vacuum cleaner. It could (probably should) have been the size of a school bus, and integrated much more solidly into the Romulan ship’s systems. Imagine trying to steal a radar system from an aircraft carrier.
2. It is easily found and identified by Kirk, and also easily disconnected, without being broken or electrocuting him in the process.
It is somewhat stretching to see Kirk waltz on in and via the Romulan's eye-motion alone figure out what and where it is. I'll agree in that a
ton of luck was on Kirk's side. And yet the script doesn't specify the device as being more than a prototype to replace existing technology. Technology that has a short lifespan due to various factors and needs frequent replacing, thus making it modular is a more logical choice. One could argue ostensibly that a prototype at this stage could be modular, like a PC ISA peripheral card being removed out of a PC with its case off but with power on - which is dumb but doesn't
always wreck either component. Or a more recent take, a USB peripheral, where removing it with power on won't hurt a thing.
To be fair, the device (which looks like the offspring of Nomad and Sargon and proving season 3 from the get-go had already a dramatically reduced budget, pun intended

) is conveniently placed in Trek's most overly used console set props, a cue they learned from "Lost in Space", but I suspect this scene alone wouldn't be as sketchy if the console set didn't look like the same thinly redressed set used in umpteen episodes.
If nothing else, TNG's phasing cloak from "The Pegasus" was far more svelte and smaller and did far more than cloak a ship that's more than twice the size of the ship they took it from. It also phases, going through matter. And, go figure, the Enterprise's engines didn't blow up when there's no reason they shouldn't have. Or they were lucky. At least Data admitted it would take several hours.

But that's innovation for ya. Pegasus took from Enterprise Incident what was a nifty (if not flawed) idea and played with it.
And yet I bleated on glossing over the universal translator a moment ago for the sake of getting around storytelling impasses, LOL!
3. Scotty is able to quickly figure out how this alien device that he has never seen before works, and manages to splice it into Enterprise’s deflector shield control in about ten minutes without anything burning out or exploding.
No argument from me, I alluded loosely to that in my OP. He's one heck of a miracle worker and not knowing the data and power connections, it's amazing he didn't fry himself, the ship's deflector system, the cloaking device itself, or hamper another ship's system in the process - even Scotty himself was hesitant when given the order to throw that switch. But his trick worked and we got through the episode rather than seeing a rather depressing series finale.
Now you could counter by saying that Starfleet learned the technical details of the cloaking device from a Romulan spy well in advance, but this is never suggested in the episode. Even if true, Scotty was obviously out of the loop until the last minute, the one person that would have needed to know the theory and specifications in order to get it up and running so quickly.
Yup, that one is a mistake - it would make logical sense for Scotty to know all available material than for him to hunt'n'peck at it. The only exposition the story gave is that the Federation knows Romulans had a new technology even more effective than what they had in season 1. And augmented by Klingon ships, which are faster and more powerful. A little exposition would have helped get around some of these plot holes, especially in letting Scotty show all the real juicy details. The goal was to obtain the device but his own dialogue shows he has zero knowledge of it.
But the pressures and stressors in script writing, everything to keep track of, limited time in which to do rewrites... the original episode was somewhat different in scope. Even with nitpicks, everything - even the acting - just warms up for me, despite its flaws (which still exist, every story's got them). Not everybody would agree and I can't blame anyone, it's easy to see why this episode would be seen as overrated or otherwise. It's still highly enjoyable popcorn-worthy Trek, where the episode is still more than the sum of its parts, even the rusty parts.