I can tell you from experience... we got the "delux" model because Tiffany thought she (... I...) could trim Kodiak's nails as opposed spending the $8 to get them done... I got him used to it after about a week, then tried to trim his nails with it - load of crap, the sanding pad wouldn't stay on, and it wasn't coarse enough to trim his nails. Your boxers' nails may not be as hard - but I wouldn't waste the money...
I have a high powered dremel that works a lot better... but I would rather take him to the groomer and have them do it... it's hard holding down a 100lb german shepherd that doesn't want his nails trimmed....