Hi, if you’re looking for one more opinion, here it is — although I’m no golden-eared audiophile so take it for what it’s worth

I find the Harbeth speakers to sound remarkably close to each other. In fact, if I weren’t listening to them side by side, I’d be hard-pressed to tell them apart from sound alone. Yes, some of them go a little lower and some project a slightly larger soundstage but overall they’re more similar than not. The point I’m making is that if you like the Harbeth sound, you can’t go wrong choosing any of these speakers. Choose one according to your budget and room.
To my ears, the Monitor range (30 and 40, and among these I would also include the P3ESR) are of a kind, while the Compact 7 and the Super HL seem cut from the same cloth. I feel the former are made to deliver maximum openness (naturally because they’re meant to be monitors in studios), while the latter are made to extract a few more ounces from the low-end while sacrificing a fraction of the transparency in the midrange.
I agree with Shinto: All these speakers benefit from being away from the walls. With enough space around them, they can deliver a very fast and open sound. If you have a small room, I would suggest going with the Monitor series because they are built for near-field listening. Vinnie Rossi argues that’s the best way to listen to them — pulled way into the room and dramatically close to one’s ears — and once you hear them like that, it’s hard to argue with him.
Coming to the Monitor 30 (.1 or .2… very little difference between the two), it’s a gorgeous speaker that can afford hours of fatigue-free listening. Having heard Vivek’s Graham LS5/9, I concur that the sound signatures of that and the Monitor 30.1 is close enough to being practically identical.
Regarding Jai’s comment about the bass being wooly, I suspect that has to do with the specific room more than anything else. I’ve heard these speakers in multiple rooms now, in India, Malaysia, Japan and in the UK, and the bass has felt sometimes lean but never wooly. Set up right, the Monitor 30s deliver bass that doesn’t go down very deep but is adequately tight and texturally rich.
Apart from the M30, I also have a pair of P3ESR, and if I can lay my hands on the Monitor 40, I will almost certainly lock myself in the house, seal the doors and windows, throw my phone into the fire and bid goodbye to the world.
As the others have suggested, the best thing for you to do, Aditya, is obviously listen for yourself and make up your own mind. If you’re in Bangers, you’re always welcome to come over and listen at my place. I’m out of the country for a few weeks but back at the end of the month.
(Look at this — my first post in the forum in a couple of years and I can’t stop talking. I’ll shut up now and return to my music... Blue Mitchell is waiting with Minor Vamp.)