Normally, the Redwall books I prefer are the ones where the various storylines are clearly linked together. Long Patrol fits this mould perfectly which makes for an enjoyable read.
There is plenty to like about this book. For a start, the threat to Redwall is extremely real; the south wall is collapsing and there are 1000 Rapscallions heading their way. This gives a sense of urgency to the book that is lacking from some of the others in the canon (Taggerung, Mariel, ect.). Russa Nodrey is a brilliant character and her mentoring of Tammo is interesting although most of it happens off page (not actually described in the book).
Damug Warfang is also an interesting villain; unlike most Redwall villains, he's not a fierce fighter and instead seeks to outwit his enemies. In fact, I'd argue (slightly controversially, I admit) that he's a better general than Major Habile Sinastra. Sinastra, who whilst being extremely brave and very likeable, does not really seem to have a strategy to beat the Rapscallions; all his efforts seem to go into getting them into an open battle, and then hoping for the best. Damug on the other hand, manages to avoid the fire log, get his troops onto the hill and surround his enemy, thereby effectively utilizing his superior numbers. Incidentally, this is one of the very few (if not the only) Redwall book to have a full scale battle in it; most of the others revolve either arround skirmishes or sieges. This adds another interesting element to this book which we have not seen before in the others.
Finally, we get to see the disadvantages of being afflicted with bloodwrath. Although throughout the entire series, characters have been saying what a dreadfull affliction it is, I personally thought this a load of rubbish; sure, there are disadvantages (taking unnecessary risks, higher risk of injury) but that is surely outweighed by the advantages it gives (makes you virtually unbeatable, enables you to fight on when badly wounded, makes you harder to kill). However, Lady Cregga Rose eyes shows in this book the serious problems having a berserk leader can give you. Twice she runs off from her army in her mad haste to find the Rapscallions and at one point forces her Sgt. Major to resort to barring the way with his sword to allow him time to reconnoitre properly! Needless to say, I now see what the characters in the previous stories were driving at!
No book is perfect of course and this one is no exception. There are a few flaws in it. The first is Tammo. There is a lot to like about him; he's brave, enthusiastic and, best of all, doesn't spend most of the book eating like other Redwall hares (the whole hares love food thing is considerably toned down for this book, presumably because otherwise, with so many hares around, the whole book would have ended up being about food!). However, he's spoilt for me as a character because he's not given enough time to develop. At the start of the book, he's pretty wet behind the ears and then, suddenly, as soon as they reach Redwall he's being referred to as if he's an experienced warrior. It makes no sense. Presumably, Russa and the others have been teaching him as they go along but most of this is mentioned only in retrospect. I felt like the book should have been longer in order for Tammo to get trained up properly, albeit this would have made it huge.
The other annoyance is the side story of Tansy and her friends exploring Kotir. Why? It doesn't help to explain why the wall is subsiding because we know that already; it's the tunnel dug in Mossflower to flood Kotir that has unexpectedly opened up again. It doesn't do anything to defeat the Rapscallions. It doesn't even make sense. After all, Kotir was in a pretty bad state when Tsarmina ruled from there. It's badly damaged by Timballisto and his catapault and then flooded. Redwall Abbey is then built on top of it not long afterwards. How much of the castle was left after all that? Virtually nothing, surely. The only benefit I can see from the storyline is: (a) it provides the usual Redwall feature of a puzzle/riddles and (b) it succeeds in ranking up the tension for the reader who is anxious to get back to the battle and see what's happening.
Overall, this is a good book and a worthy addition to the Redwall canon. Considering it's for children, it's extremely well written, has a strong plot and is full of likeable characters. What more do you need?