> What problems am I likely to face?

Vendor lock in! i.e Your vendor will change the spec so you have to buy the new version.

And of course with a proprietary product you don't have access to the source, so you can't improve it. Or learn from it. Or use it on more than one machine. I'd always plump for the product that gave me the most freedom to use, modify, share and improve it, which is always going to be the one that's Free(as in freedom) or Open Source Software, unless there was an /extremely/ compelling reason that I couldn't.

Technically hibernate and nhibernate also look (from first glance) to be more powerful tools:
http://www.hibernate.org/263.html compared to http://www.ideablade.com/technical_overview.html

YMMV.

tar




--
Don't Stand on your head - you'll get footprints in your hair
                                           http://charlieharvey.org.uk
                                              http://charlieharvey.com