Aggressive itinerary in Viet/Laos/Camb/Bangkok, all opinions welcome

I would drop Vientiane if I was you. It's not an unpleasant city, but it has little in the way of specific sights, and is certainly not worth flying in and out of just for a day and a half there. If you want to include Laos in your trip, and get a bit of a feel for the country, stick to Luang Prabang. Spend 3-4 nights there, instead of trying to add Vientiane too, would be my advice.

Your itinerary is on the aggressive side. But you already know that.

I'd say choose only one beach place, either Mui Ne or Nha Trang. The advantage with Nha Trang is you can use overnight train or bus to reach it, since you don't have a lot of days to waste. Or skip both places, fly to Danang, and do your beach time at Ang Bang, just outside of Hoi An.

And there's no reason to include Vientienne at all on a trip this fast. Just fly from Luang Prabang to Siem Reap, and go to Phnom Pehn afterwards. Because there aren't direct flights between LP and PP, but LP to Siem Reap you fly direct.

So it is possible. But is it a good idea? Really I think you'd enjoy your SE Asia trip more if you only include 2 countries in your roughly one month to travel, and include a few more places in Vietnam.

And also the combination of heat/humidity in July is oppressive and punishing in many of these places. It can slow you down for sure. Afternoon monsoon thunderstorms do cool things down, but that slows your day down too, since you have to wait out the storm someplace dry.

I agree with #2 that you may consider skipping either Mui Ne or Nha Trang or both. Personally I find Mui Ne is more beautiful and interesting. If you skip both Mui Ne and Nha Trang to add Phong Nha on your list, you can check out Vietjet flight from Can Tho to Danang. From Hue, you can take train to Dong Hoi (to get to Phong Nha) and then train to Ninh Binh and finally to Hanoi. Ninh Binh in July is not the most beautiful but still nice.

Vientiane is not special in comparison to Luang Prabang, so you should pershaps skip it too. Vang Vieng is called "backpacker heaven", where you can do some activities like: kayaking, cycling, tubing, hot-air balloon taking....quite interesting too, but it takes some hours to get there either from LP or Vientiane.

Add a day to Luang Prabang.
One full day in Saigon is plenty - it’s not very interesting.
Hire a car for the drive from hoi an to hue as there’s lots to stop off at (this is standard and easy to organise).
You could also drop Phnom Penh and give yourself an extra day in Bangkok.

Leave it open.,start at the beginning and go as fast or as slow as you want.That time of year you don't need to book anything much in advance.

When your time is running out,go to your last stop and fly home from there...

I'm highly interested in anyone's thoughts on what I'm so far thinking

Anyone's? You asked for it ..

I've backpacked a fair amount and I tend to get itchy toes and like being on the move a lot

Is it safe to assume that you have a good idea of what you like to do and how to do it? Certainly better than me, I am sure, because my only experience with you is with what you have written here.

OK, here's my problem. A half-year in advance you are planning a one month trip down to the day, and asking other people what you could leave our or add or substitute with something better.

Is this sort of long-term micro-management really consistent with itchy feet? If you know yourself, and with the necessary experience, why the uncertainty?

I always take my trips along the lines of what #5 suggests. I have a rough idea of my route but it is always open to spontaneous modification. If I get tired of where I am, I move on. Or I stay longer if mood and interest swings in that direction. What I finally end up doing usually fits the overall plan 80-90% but the details on a day to day basis fits only 40-50%. This should work whether you stay somewhere 1 day or 6 days.

So, haven't you done enough thinking about all this, for someone who likes to be on the move every second day? How can you optimize such a plan? You can't. Just go and do it, and see what you end up with.

Thanks to everyone who has responded so far. Lots of food for thought.

Regarding Vientiane, my gf is half laos and wants to visit the capital because apparently that's where her ancestry is from.

bthdth: like I said, its a rough guideline. Not at all in stone and for sure will change during the trip.

Since I haven't been to these places, and many are hard to get to, its nice to know if the effort isn't worth it or if someone recommends something else. Seems logical to me.

Plus I like to write it out by the day so I have an inkling if what I'm proposing will even fit into the days I have available to me. That doesn't mean I will follow it to a 't', but it does give me an idea of how often I'll have to be on the move, etc, and with the help of some answers already given, where I can cut out a day or two here and there because things never go completely to plan. I usually try to have at least a few free days in there to allow for problems that arise, and now I know a few places that could be turned into free days. Appreciate all the input.

One really nice thing to do in Vientiane is to walk with the locals along the riverfront path in the early morning.

Phong Nha was cool when we were there about 4 or 5 years ago. Undeveloped, chilled out, lots of caves to visit (one day we did an organised trip but you can do it by motorbike, another day seeing a cave by boat).

Vang Vieng was fun, chilled out, drinking and the tube down the river thing.