Sentinel Columnar Apple Trees

I saw an advertisement for Sentinel Columnar Apple Trees in Territorial Seed Company's catalog. I was wondering if anyone has grown these and how they fared. I have never grown a fruit tree before, and these seemed very unique and interesting. I am in NE where the winters are very cold and windy, and the summers very hot. If anyone has any advice or feedback for me I would greatly appreciate it.

Columnar trees do not look to be very productive to me. I would suggest a dwarf tree instead. You would have to stake it but they produce quite well. Also you can go to Dave Wilson and he explains how to prune a larger tree to keep it small. Scottsmith is experienced in growing trees in a small area.
RED

I have heard they are not particularly tasty, but a few people do like them. I would agree with Red, just get a dwarf tree and prune it tall and narrow and you have something similar but with good taste and hardy in your zone (only about half of all apple varieties are hardy in 4b)

Scott

Thanks for the tips. It looked like it would be fun to grow, but a lot of work and not as interesting if it didn't produce great fruit. I know the local bush/tree center down the road has varieties that are supposed to do well here, so I will have to do more research.

I was also looking at the columnar trees (also sold by Jung's). Another concern for our region (southeast Nebraska zone 5) - while the trees are advertised as being 'disease resistant', I could only find information that they were scab resistant - out here cedar apple rust and mildew resistance are a bigger advantage.
I'm thinking about the mini dwarf apple trees offered here http://www.raintreenursery.com/catalog/producttype.cfm?producttype=Apples%20Mini%2DDwarf, more of a selection than the 3 columnar apple varieties offered

I bought an Enterprise two years ago. It hasn't fruited yet, but so far it hasn't shown a sign of the rust, which is the big problem here.