A warranty company I worked for subbed all our claims out to value doors, they could supply and fit any composite door for less than we could buy them and they included a 10 year warranty in that as well, never had any complaints fed back so assume they were adequate to good. In terms of construction solid core vs foam core i've never really found a great deal in it when it comes to fitting, quality, use etc, solid or foam without a doubt will crack if they're a dark colour and south facing well before the 10year warranty is up so make sure your warranty covers sun damage as some don't, ask value doors to highlight on their T&Cs where it says they are covered, no good them saying everything is covered for 10 years only for them to say in 5 years time apart from sun damage
