I'm thinking of buying some new 4 season boots and the ones i have in mind are Scarpa's M4 Mantas. They seem like a good all round boot from what ive seen.
But does anyone have any experience using crampons with them? I have a pair of mountain technology ice mountain 12 point crampons, which are not bad just wondering if they will work well together??

Depends.
For example, depends on the size of your feet....some crampies fit better on the same boots than others dependent on foot size believe it or not.

The ONLY way to find out is to: <rings bell>

Go to a reputable dealer and marry the boots and crampies together.
There is NO OTHER WAY to be sure.....

Have the Scarpa Mantas and would recommend them (assuming they fit you) - I use Grivel crampons with them - again absolutely great but doesn't really answer your question. As JJ says you really have to try them on, both for fit of the boot as well as how your crampons fit.

Thanks steve and JJ i think im pretty sure the manta's are the boot for me, have tried them on and they fit well and feel sturdy.
I will take your advice JJ, i will have to search around and use a little trial and error untill i find the perfect match!

peter. what size are your feet ?.
have a pair in 43/9.5 that have seen only 4 days use. 3 of those on snow and 1 on trails. bought in march 2005 from ultimate outdoors.
awesome winter walking boot and i love em. except, i discovered at the time that my feet run cold and need something more insulated. got some salomon sm lites cheap, so i'm selling the Scarpas for 100 quid.
let me know if this is any good for you !.

Got M4s and love them. I tend to wear them year-round for scrambling and when carrying a big load as I find them supremely comfortable, grippy and with great ankle support.

If you're buying new, make sure you get the new(ish) M4 Manta Techs with the newer Vibram sole and better lining (you can tell by the green dot on the sole). Many shops are still selling the older version (at the same price).

I use size 45s and they are fine with Grivel G12s. But as everyone says, you need to go try.

peter, i'm size 11! I think with a pair of socks on the 9.5 would be a bit small, cheers for the offer any way.