I've the Boss ME-50 and it's cracking pedal. I'm sorely tempted to upgrade to the ME-70 as they've improved it immensely.
One *major* consideration when buying a multi fx pedal is ease of use. Many pedals are made affordable because they reduce the amount of controls (knobs) available, so say, a pedal might have four knobs, these are assigned differently depending on the settings, distortion, delay etc. etc. This means you can't just twiddle a control at will without selecting that effect first (I hope that makes sense?). Looking at the picture I think this is the case with the ME-25. Personally (and it is personal preference) I can't be doing with laborious button pressing when I want to change something simple. I bought a Zoom pedal some time ago that was of this sort, couldn't be bothered with it at all, just too much hassle.
Something like the Boss ME-70 has dedicated knobs for each effect so it's just like bolting together individual pedals, much much easier to use. There's a lot more to it than just that but essentially it's (in my case ME-50) a joy to use.
If you can stretch the budget to this, I guarantee the lad wont be disappointed. If someone bought me a ME-70 I would wet myself in sheer delight.
Boss ME-70 Guitar Multiple Effects: Amazon.co.uk: Musical Instruments
Can't help you on the Line 6 stuff, maybe somebody else can?