Ghost 13 GTX

Hopefully you have the opportunity to try both on at a local store, but from all the reviews & marketing, the Superblast 3 is definitely targeted at your paces moreso than the Megablast. I ran a lot in the Superblast 2 - definitely hit its sweet spot for me around 7:30-8:30 min/mile pace for me, was a little clunky but totally usable at slow paces over 10 min/mile, didn't mind it at all if my legs were beat. I recently picked up the Megablast - I think it is definitely less clunky than the SB2 at both fast and slow paces, but does feel better when I'm putting a lot of force into each stride (I start to feel the springlike bounce). At slow paces it's soft and more ordinary. Planning to use that as my next half marathon race shoe and have been only using it on long runs with tempo sessions. I have not run in the Superblast 3 but reviews say it's softer than the Megablast (so maybe more comfortable), more stable due to the EVA base foam, and also has a more comfortable upper (the Megablast has an ultra-thin, hard, non-stretch racy fabric). I also used to run in Ghosts (all the way from version 7 to version 16). The Asics -blasts are a huge change from the classic Ghosts! The blasts are so light for their size and will feel like clown shoes in comparison. Definitely get used to them before racing.

What kind of trails are you running? I probably spend up to \~40% of my running on trails but it's mostly decently packed, gravel, or grades under 10%. For all that running I just use my normal daily trainers like Brooks Ghost and Asics Superblast because my loops have so much road on them - no problems at all. I generally only break out the real trail shoes (Brooks Cascadia) when doing much steeper trails for the grip on the lugs and better protection from poky stuff. The most basic $140-$150 daily trainers like Brooks Ghost and Puma Velocity Nitro have quite substantial outsoles and good durability, but no big lugs. The lugs are the main part in question - the bigger they are, the more extra grip in dirt/mud/leaves - and also the less durable they'll be on road. In theory I would also use my trail shoes for trails in terrible condition (tons of rocks and roots) but in actuality I usually end up avoiding those trails because I find it hard to maintain a good aerobic pace and also reasonably avoid tripping and falling. In fact this past fall I took my Superblasts on a 14-mile mostly trail run with elevation and had 2 bad trips where I narrowly avoided wiping out very badly, and honestly the shoes had nothing to do with it other than maybe encouraging me to go too fast (possibly being 12mm taller than my other shoes also hurts). Just was descending and not maintaining my focus on some probably root/rock/obstacles as I fatigued. The main shoes I try to keep off anything but the best condition shoes are my more speed shoes like Endorphin Speed 4 where the outsole is more minimal and I feel the midsole foam just looks like it'll chunk apart if I step on a rock.

It really depends what kinds of trails. I run very regularly on light trails (packed dirt or packed gravel) with road shoes, honestly if the trails are in good shape it literally does not matter what the shoe is. For slightly rough trails, as long as I have a decently robust outsole to protect the midsole from from sharp rocks and roots, road shoes will still be OK. Shoes like the Brooks Ghost and Puma Velocity have been good for this kind of thing for me and have been most of my normal miles. I have found myself traveling and running on trails where I have to go much slower over tricky bits, particularly steep descents, but honestly I'd still have to slow down with trail shoes, and it's generally safe as long as I'm not worried about my speed. If you are obsessed with ego / speed / performance, then the trail shoes I suppose are a must. Trail shoes for me become most helpful with very steep (over 10% grade) or very loose terrain (mud, muddy grass, or heavy leaves are the most challenging). My trails shoes also have a little more protection around the toe cap which is nice bonus for loose or rooty trails. But racking up significant miles on pavement, good lugs will just wear out too fast, I don't think it's worth it.

The overall fit and shape of the Superblast is very similar to the Novablast. However, it is definitely firmer. The Novablast felt way softer and bouncier. I just hit about 30 miles on my SB2 after getting them the previous weekend, so will have to pay attention! So far have loved them on a 12 and a 13 mile run. I think the Superblasts feel good to me at easy paces, moderate paces, and 5 mile tempo paces, but nothing special if I kick it into a stride/sprint - I'd rather a more compact shoe (like the Endorphin Speed) for a 5k or speed workout. However, despite the stiffer foam, the cushioning effect (from the height) of the Superblast is still way more than the Ghost (I also ran in only Ghosts for 10+ years) - the Ghost has 10mm less stack on the heel and nearly 20mm less on the forefoot. I think if you love the Novablast you should keep running in them and they could even work for a marathon. The main reason I got the Superblast is the durability and cold weather performance seemed more worth it in the long term, and I felt the firmness is actually a good fit for me.

Personally I prefer a medium-stack flexible daily trainer for do-it-all travel. Such as Brooks Ghost, Saucony Ride, Nike Pegasus, Puma Velocity Nitro, etc. Flexible and comfortable for walking and sitting on the plane, enough cushioning to do up to \~13 miles, not too expensive if they take any travel-related damage. I find supershoes like the Superblast/Megablast too tall and rockered for normal walking and any potential rocky/rooty trail runs. And the tempo shoes like the Boston 13 or Endorphin Speeds stiffer than I want for everyday comfort.