since i can't help but try new stuff, i just bought the new hardsided basket to replace my full mesh basket in my 15G system. it has the new sparge setup with the 2 x tri-clamp attachment and the short return tube. i did a double brew of two lagers and started at 7am and finished at 5:30pm not including clean up. 4.5 hrs for each brew (i took a break in between) including cooling. few things to share.
1) the wort in the kettle is not as clean as with a three vessel system since there is material that makes it through the bottom screen but not back up through the grain bed whereas with a three vessel that would be left behind in the mash tun. that said, after cooling i let it sit for 20 mins and then racked into my fermenter and the wort was noticeably cleaner that with the 100% mesh basket. so during the boil the wort was a little bit cleaner than before but into the fermenter it was noticeable cleaner. i gelatin most my beers and have had excellent clarity anyway but this has reduced my trub in the fermenter. my guess is that some larger stuff makes it through the screen and settles to the bottom of the kettle but the haze in the liquid gets filtered out by the grain bed. so when you let it sit after cooling that large stuff just settles to the bottom.
2) i did not have any issue with the sparge arm attachment. it screwed it down under the lip of the kettle and did didn't move at all. i didn't tighten it down hard because i didn't want to scratch the kettle. that is my one concern is that it screws down against the outside of the kettle and some sort of rubber coating on the end of the screw would be nice. i think a lot of it depends on how your run your hose up to it from your pump and how hard you recirc. my hose comes straight up from my pump with no bend and i ran my pump about 1/4 open to make sure i didn't cavitate the element. no issues whatsoever.
3) i also moved to a 4500W ULWD element and that has been a good improvement. on my batches i start boiling with about 7.75G of wort and i have to run the element at 75% to maintain boil. when i recirc through my counterflow i have to run at 95% to maintain a strong boil. but now i don't have the pulsing that i did with a 5500W element. also, my 5500W element was straight and i had some minor scorching. so far, the 4500W ripple element has been much cleaner at the end of the brew session. i didn't really notice much of time difference in heating up water. i'm sure there was but maybe a couple of minutes.
