I am tryiing to decide between these 2 half day Glacier hikes at Skaftafell. Does anyone have an opinion about Glacier Guides vs Icelandic Mountain Guides in general or these particular hikes ( is one in a more interesting/attrative location than the other? does one have a reputation for using smaller groups or being more strenous). i believe IMG is an bigger/older company than Glacier Guides but that can be a good or a bad thing. We will be there in the middle of August. T/hank you.