This is what I use for long runs and so far used for a couple of marathons. No wobble and a big pocket for gels etc. Better than cheaper versions Ive tried (Karrimor)
Sorry dont know much about the differnce between the two types of Mudclaw (believe number is weight in grams?), but just want to say I have some 333s and love them. Use them for XC races, offroad Marathons (ie Beachy Head). Nothing stops them they are brilliant. Wouldnt want spikes. Got mine for £50 odd online, believe from Start Fitness.