Bests & Worsts Reviews from Amazon

Bottom line: I was expecting the Double Boiler to blow the BES840XL out of the water when it came to shot quality. That was not the case at all. While the milk texturing capability of the 840 is a pale shadow of the DB, and it lacks the multitude of convenience features of the DB, the 840 absolutely holds its own with regards to shot quality. Full review: I've been using the Breville Double Boiler espresso machine for nearly a year and have been very pleased with it. I was hesitant at first, but great shots and the many, many convenience features won me over. So, when the opportunity came up to compare their top of the line Double Boiler (DB) with their new machine (I'll call it the 840) I thought it wouldn't be a fair fight. Well, I was wrong. I've never been a fan of thermoblock machines since the temperature stability is just not there. Breville seems to have solved that using two methods. First, the thermoblock is really a thermocoil -- it's a solid block of metal that has two channels machined through it: one for water, the other for the heating element. Cold water enters at one end and emerges heated at the other. They also added a PID for temperature control. Collectively, these techniques produce excellent temperature stability for shots, and very fast recovery time. The machine itself is classic Breville design -- lots of stainless and high quality plastic. It has a small footprint, and looks much like the baby brother of the DB. But it's the shots that count. I started with an easy test: Lavazza Super Crema. It's not a high-end bean, but tasty, and one that I've found is very forgiving of less than perfect prep. After a few test shots to get the new machine dialed in, I pulled a double shot from both machines. I could not taste the difference. Did it again and had others taste it, and they agreed with me -- no appreciable difference in taste, mouth feel, crema, you name it. The next test was a little more challenging -- Lavazza Dek decaf. Decafs in general are (to my palette) more sensitive to temperature variations, and the Dek is especially sensitive. Again, both machines produced the same quality shot. The 840 seemed a just a bit less consistent when I did back-to-back shots quickly, but the difference was very minimal. My final test was with one of my favorite beans - Red Bird. This is where I did taste a difference between the 840 and the DB, but it was subtle. The shot from the DB was more creamy and full-bodied. But the 840 shot was quite good as well. The small differences became almost nil when I made Americanos from Red Bird. For my tests I used my Baratza Vario grinder for both machines. While I have a Breville Smart Grinder it does not pair well with the DB (although it is excellent for any non-espresso use). I tried it with the 840 and got better results, but still much prefer the Vario to the Smart Grinder for espresso. Still, the 840 appears more tolerant of lower-level grinders. I also found I needed to go slighly coarser with the grind for the 840 than the DB. The DB does pull ahead strongly in two areas -- milk foaming and convenience. The thermocoil just can't match the steam production of a dedicated boiler. It did a decent job with milk (albeit with the annoying thump-thump-thump sound that every thermoblock design makes), but it was much slower than the DB and the steam was a lot wetter. Functional, but not at all impressive. As expected given the price, many of the DB's convenience features are not found on the 840. However, the 840 does have a few of the DB features such as a dedicated hot water dispenser. This is operated with a knob (turn one way for steam, the other for hot water). It splatters more than the DB when dispensing, but the temperature is spot on: I got 197 with the 840 and 197.5 with the DB (same thermometer held in the water stream for 10 seconds). The 840 also appears to have the same excellent quality head gasket as the DB. The portafilter is well made, although I was really disappointed to see that it was 54mm, which means I can't use my 58mm VST baskets, tamper or the bottomless portafilter I have for the DB. The included tamper is decent quality, and stores easily in the machine. The shot volume is programmable and can be overridden in manual mode. It has a three-way valve so you can backflush (plus it keeps the puck dry). It has an automated cleaning cycle and a "clean me" light, which is handy. Misses are often related to convenience issues. I wish it was a bit heavier or had better gripping feet, since it's relatively easy to jar when you're putting on the portafilter. A bigger water tank would also be nice. The thing I missed the most was a water level indicator. I didn't expect it to have all the bells and whistles of the DB, but no water level indicator? That seems to be a basic feature that should have been included. My concerns are two-fold. Breville does not seem to have mastered the reliability issue with their espresso machines. I'm on my second DB, and it is again starting to act up. The Breville customer service has been great in replacing machines, but I'd rather not have to deal with that at all. Plus, with only a one year warranty and no local service centers, I don't have the warm fuzzies about getting years of service out of either of these machines. My second concern is about scale build-up. It's harmful in any machine, but truly deadly in a thermoblock/coil design. Breville includes their water filters (the same as with the DB) and recommends a descaling every month and a filter change every 2 months. The fact that they are taking such precautions tells me that they are concerned as well. If you get this, don't skimp on descaling! But those concerns aside, I'm really impressed with the performance of this machine given the price. While it is not perfect, it holds its own where it counts: what's in the cup. This is definitely a machine that should be on your short list in the under $600 category - don't let the thermocoil design scare you off in favor of a SBDU design. At this price point it's a 5-star machine. I'll update this should reliability issues warrant a revision in the score. Sorry for such a long review, but feel free to post a question if there's something I didn't cover.