GM - Overdelivered. I purchased an Argon OLE from PDS, which was lovely, a little blemishy on the outside edge, but was all sapwood and had 7 straight and even grains. However, there were these strange cracks on the outside edge, so I emailed GM about it. (Had emailed about a cracked bat first, which I didn't expect anything from) Steve from Unicorn told me to send it back to GM themselves, and the day after they received the bat, I received a letter, telling me that it would be replaced. (Friday) So Monday comes along, and I receive the new Argon, which is a little grainier, has a hard bar, and felt a little harder. However, after some knocking and tapping up, safe to say I was very pleased, and happy with how quickly GM sorted it out. I thought they would tell me to go through the retailer, but was nice of them to replace the bat so quickly. Had 3 Argons pass through my hands, all of which are/were exceptional bats. Sad to see it dropped from this years range, as I am not a big fan of the Octane! (Still the Aura should be good!)
GN/Lords - Underdelivered. Sent a bat for a rehandle under warranty near the end of June, and received it back... At the beginning of September! This was partly due to GN taking their sweet ass time, but also the staff at Lords seemed completely incompotent, they must have taken 2 weeks or so to deliver the bat back!
Laver - Overdelivered. Laver made me a Reserve around April of 2013 I think, which was incredible. I was initially not too impressed from the photos, but when I received it, I was in love with the bat. Safe to say they overdelivered too by letting me send the bat to them for a free refurb/repair, thanks to some delamination problems, and I also ordered a copy of the bat. The copied bat itself I feel actually exceeds the original, which is an overdeliver in my books! (Not actually used the copy yet, but in terms of pick up and responsiveness, seems to be better)
H4L - As expected. Great bats, but as expected. The current H4L bat I've got is currently being knocked in, and I feel that may sway my opinion slightly!

Red Ink - Underdelivered/overdelivered. Asked for a custom made G1 bat. I said I cared a lot about it being a decent size for the weight, and didn't really care too much about the looks. Ended up getting a pretty ugly looking bat, (Would have graded it a G3/4) and it responded pretty well, but wasn't exceptional. (John had gotten the cleft as a G1 from his supplier) Couldn't get on with it, so shifted it on. I did purchase a middling bat too, which John overdelivered on. I think I paid £45 posted for one back then, and the finishing on that was top notch. He also shapes a cracking oval handle. Partly my fault that the bat was underdelivered, as I went for a slightly lower weight, but also because I didn't pick my cleft, and I think because it didn't look in any way aesthetically pleasing, I wasn't so impressed.
Salix - Underdelivered. Purchased my one from Paul at IJC, and to be honest, it was pretty bottom heavy. (Pod Players) Lovely bat, my brother took it out my kitbag, but with all the talk about how Kember balances bats to perfection and makes them pick up exceptionally, safe to say I was pretty disappointed! I did get a HH Super G1 which picked up really nicely however. (Not entirely sure it was made my AJK though)
Newbery - Underdelivered/As expected. Hard to gauge this one, the Tour I bought, it felt odd in the hands. It was a cracking bit of willow however, and I feel that it was thanks to my fear of damaging it (Had sought after it for a while) I couldn't wield it properly. Had such a large playing area, and looked stunning!
Vantage - Overdelivered. My first custom bat experience, and had set the benchmark for the customer service I expect from Custom bat suppliers. It was back when Mattw ran it, and I had requested for 2 big copies of the Series 1 and 3 profiles with no concaving. First bat I received was actually a concaved Series 3, which was a little disappointing, as it was so nice! (This was my fault, as I had originally asked for a Shadow profile, so the batmaker had already started concaving the bat when he received the altered request) The bats I received in the end were beauties, but ended up going slightly lighter as I got unfitter. (They were 2.13)
Plenty more I'm sure, but this will do.