EBC or Annapurna Circuit

There are a number of differences between the two treks you mention. Here are some facts for comparison:
Everest Base Camp...most people begin the trek at Lukla (2850m_approximately 9350 ft) and within 2 days you are already at 11,319 ft at Namche Bazaar on most standard itineraries (of course you could take an extra day to help with acclimatization). By Day 4 you are at approximately 12,500 ft at Tengboche and the next day you are above treeline and over 14,000 ft in Periche or Dingboche. You spend more time at high altitude and above tree line on this trek than on the Circuit. The mountain views are generally more open and absolutely spectacular. Your high point is about 18,500 ft at Kala Pattar view point - 1000 ft higher than Base Camp. Once above Periche there are no more permanent settlements so you tend to see less of real village life. The Sherpa people, again generally speaking, tend to be more affluent. The dominant culture is Sherpa with very little exposure to other cultures unless you start your trek at Jiri and walk in rather than fly. I've been there more than 10 times and am still in awe of the scenery!

Annapurna Circuit ...this is a much longer trek mileage wise even if you add ChoLa Pass and Gokyo Lakes to your EBC trek. You start lower - less than 2700ft at BesiSahar and spend a lot of time during the next week climbing and descending, gradually gaining altitude until reaching Manang (11,641 ft) - your high point to date and first acclimatization day if you have followed the main trail along the Marsyangdi River. You've spent a week strengthening your legs and your lungs for what lies ahead in the next few days. The trail started out in farm fields/terraces and subtropical forest and has gradually climbed through rhododendron and oak into fir and pine forest onto the more open arid slopes surrounding Manang. The culture has also evolved beginning with Indo/Aryan, Hindu culture during the first few days of your trek and moving into enthic groups originating in lands northward and a dominant Buddhist culture - even the architechture changes as you progress through different eco-zones. Above Manang, the terrain is much rougher and rises more quickly to the foot of the Thorong La (pass) at Thorong Phedi (14,600ft) although the distance from Manang is relatively short, because of the elevation gain it is usually recommended that you spend 2 nights in Manang, do a short day to Yak Kharka or Letdar (13,780 ft)staying overnight before going on to Thorong Phedi. The following day, crossing the pass (summit 17,769 ft) is a much longer day than most in the Everest area (23 km to Muktinath with a 3300 ft gain to the pass and a descent of 5300 ft to Muktinath) Most people find it a tough day and it is one that requires good, stable weather conditions. Once on the other side there are ancient trade route villages to explore such as Kagbeni and Jharkot and Tukuche. You are in a rain shadow area of eroded sandstone - quite different than the east side of the circuit until you get below Tukuche. The Kali Ghadaki River valley is broad and open until below Tukuche. Mountain views that you had on the eastern side begin to be less open as the valley narrows and the ecozones reverse themselves as you descend down the valley. Below Ghasa you descend quite rapidly and by the time you get to Tatopani (hot springs) you are down to 3900 ft. in a sub-tropical forest with banana and orange groves. There is huge diversity in both eco zones and culture on the Circuit. It's a cross section of Nepal - whereas in Everest you see predominantly one ethnic group and one religious culture Sherpa/Buddhist. The route climbs again to Ghorepani at just over 9000 ft in the next day (sometimes 2 if you are taking your time) and takes you up to 10,476 ft at the top of Poon Hill and then descends again all the way to the trail end at Naya Pul about 3300ft. So less time at high altitude but more mileage and a lot more ups and downs. There are wonderful mountain views on the east side of the circuit, over the pass and at various places down the west side along with a spectacular morning on top of Poon Hill...but there are also days when you will not see the mountains, but will have wonderful forests, river and gorge views.

Hard to compare the two - I like them both - for different reasons - so wherever I am, I tend to like that place best at that moment. You will enjoy either one - just be sure to take enough time to absorb your surroundings and don't fall into the trap of trying for a speed record - that isn't what trekking is really about.

Intrepid Travel is a reliable, reputable foreign owned company. They are good at what they do. There are also many good trekking companies in Nepal who do an excellent job and give great value for the prices they charge. Their profits stay in the country and benefit Nepali people. Something to consider when making your decision.

Intrepid is an Australian-owned company that is really reliable, eco-friendly and a heck of a lot of fun! I have done several trips with them in southeast Asia and South America and they have always been really great...small groups, local leaders, like-minded people, great prices! That said, I don't know a single thing about trekking in Nepal...but I'm sure you'll have an amazing time!!

I would recommend you Annapurna circuit. These treks begin from low elevation and enough time to adopt high altitude. Obviously this best trekking trails too. I did not use Intrepid; I did use Yala Tours in Kathmandu. They made fabulous arrangement of your Jomsom-Muktinath treks. You can Contact mr. Gopal owner of Yala Tours, he is very helpful.


Thanks

Having trekked both AC and EBC 3 times between -84 and -06 I would now recommend Khumbu (EBC). Road construction all along the AC and the ugly scars it has caused and motorized vehicles in Kali Kandaki valley have taken away a lot of the magic there used to be on AC. EBC trek, preferably starting from Jiri, is more pristine in this sense and mountains closer and higher.

) I perfectly understand local peoples rights to progress, it is their land.