I'll put up the hands first, and then comment.
I bid 3NT, down 1. This may get lengthy since I found the hand a challenge and I want to respond to various thoughts
Hog says 3H is forcing since with a non-forcing hand (possibly this one) partner would bid 2N Leb. Very possibly we should play this way, but we do not. We have trouble defending against the weak nt, and all suggestions taken seriously, this definitely included, but at the time this was played, that's out. I mentioned that partner and I differ a bit on what the double of a weak nt requires. I am of the hog's view that this is the least I would do it on and I wasn't all that happy about it. When I double any nt I like to have an idea of where the tricks might be coming from (ok here) and I like to have a lead that won't blow a trick (not so clear here: I plan to lead the ace of clubs but if declarer has Qxx and partner a stiff this won't be so great). Partner is more of the opinion that you gotta get in there and fight. We haven't resolved this.
Our style when flying a bit blind in undiscussed auctions is along the lines of: Most bids are not forcing. Assuming this style is in force here, partner's 3H can be taken as: "Based on what I have heard, I am willing to place a bet that 3H is right". In this light, I think I need to pass. My hand will not be a disappointment to partner when I spread it, but it won't be a cause for celebration either. So, as we play, pass seems right.
Before we wrap it up though, let me change the opponents hand just a little:
I have given E a four card heart suit by exchanging a club spot for a heart spot. Certainly a reasonable exchange. The bidding would presumably go exactly the same. Now there is no way to stop a heart contract from scoring four hearts, five clubs and the ace of diamonds while 3NT still suffers the same fate.
I am aware that moving cards around to make a contract work is a bit suspect but it seems more justified here as firstly you get dealt more four card holdings than five card holdings and secondly even weak no trumpers may choose 1H here if they decide to open this. I didn't check the score sheet bu I can imagine a third hand 1H being overcalled by 2C after which we outbid them in clubs even if they find their spades.
So my conclusions are: I should have passed, it's a close call, there is something to be said for 4H (I considered it) if I am going to bid. Whether this hand should be seen as a showcase for the weak no trump is less clear to me. It seems more to highlight the importance of not opening 1H when the guy on your right has five of them.
Thanks for the responses and I would be happy to hear more about effective defenses to the weak nt.
Ken