I want to share my experience and I hope it will save some people time and improve their experience with wonderful Lelit Elizabeth machines.
Q: Puck often sticks to the shower screen and/or a good amount of coffee still remains in the basket after tapping.
A: People on forums often say it is normal or suggest trying other (fresh) coffee. If this hasn’t helped you (like it was for me), check your basket. Stock Lelit double basket and some IMS baskets (for example, popular B702TH24.5M or B702TH26.5M) have rounded internal corners at the bottom. I used IMS B702TH24.5M basket for a year and I had sticking pucks or mess in the basket 7-8 times from 10 with various coffees, doses and grind sizes. Sometimes (with lighter roasts and/or smaller doses, 16.5g in my case) tamper would go to the top of the rounded area and get lightly stuck there - you could feel it. It means you can’t fully tamp your coffee, and it can be a big reason for a mess after the pull.
I’ve switched to a straight-wall IMS basket (for example, B702TCH20 or B702TFH20) and now pucks stick to shower screen 1 in 10 times - and only when I leave portafilter in the head for a couple of minutes. If I remove portafilter right after pulling a shot, I get dry pucks sitting tight in the basket, and an almost clean basket after tapping.
Q: what IMS basket should I choose? what’s the difference between IMS Competition, BaristaPro and E&B Lab baskets from IMS?
I’ve used baskets from all 3 IMS sub-brands and can confirm they all have identical or indistinguishable finishes (unless you buy nano-coated one, of course). The differences are: straight vs rounded walls at the bottom, flat vs convex bottom, number of holes+pattern.
Here is the list of baskets I tried with my Lelit Elizabeth and my thoughts about them:
B702TH24.5M (IMS Competition) - used for a year and I regret it as it was a reason for messy pucks (see above) and trickier dialing in for new coffee bags. 641 holes. Also it is too large for 16.5g load recommended by @DavecUK .
B702TFH22 (E&B Lab) - straight walls (good), flat bottom, 715 holes. I found it the best of all I tried. It is probably less forgiving compared to 641 and 661 hole versions but I found dialing in the easiest. 22mm version is ideal for 16.5-17gr dose - I tested it on both dark and light roasts.
D22661 (BaristaPro) - straight walls, flat bottom, 661 holes. Identical to B702TFH22 but has fewer holes which slightly lowers extraction (all other variables being equal) and makes it less favorable for me.
B702TCH24 (IMS Competition) - straight walls, convex bottom, 715 holes. Identical to B702TFH22 but has a convex bottom which creates a nicer single stream of coffee in a bottomless portafilter but hides uneven extraction (compared to B702TFH22). Keep in mind that capacity-wise the 24mm version of this convex basket is nearly identical to 22mm flat bottom version.
I have NOT noticed any dramatic difference in espresso taste or crema level from the baskets but I THINK my current B702TFH22 makes the taste most intense/concentrated. Baskets can quite significantly change your experience from using LE though.