Originally Posted by roscoetuff
To me, OP should define the specifics they like about XTOL. I would assume sharpness, and possibly eco-friendly, etc. But frankly, from what I've seen, there is no developer that is so much better than others that is not affected equally by your choice of film and choice of technique as well. You can get seriously impressive results from a whole lot of combinations, but the best use of your time is to improve shooting technique and eliminate variables.
Biggest improvement in technique in my case was picking up a Jobo. While this chooses a particular type of agitation, it also narrows choices in suitable developers. I've made lots of mistakes and even attempted to use Replenished XTOL in a JOBO - which in a word.... increases the likelihood of XTOL-failure from oxidization. XTOL is nice, but my enthusiasm for it waned, and after speaking with the USA Jobo reps (Cat Labs JP), I tried Bergger's Berspeed and have been very pleased with the results using Ilford Delta 400 at box speed.
Your mileage may vary.
I found that Xtol improved all films in pretty much the way Kodak described - better speed with finer grain and better sharpness than HQ or PQ developers, and with tonality very similar to D-76 (desireable to me).
Kodak gave times for rotary processing with replenished Xtol in the Xtol data sheets but if you read Kodak Technical Publication Z-133E on process control, they make it clear there is a lot of work in maintaining a replenishment system. The main thing I found when I worked with a replenishment system was that the only way that replenishment is worthwhile is if you are developing a lot of film (10+ roll/week minimum - i.e. using it all the time) and that the decrease in sharpness with replenishment/seasoning didn’t make up, for me, for the even finer grain it gave compared to dilute Xtol used once. I used a 15L replenished Xtol dip-and-dunk system with nitrogen burst agitation for a long time when working in a commercial lab, but never tried to do it for myself. Even if you make up 5L of Xtol and follow the re-use instructions, you need to use it quickly.
Berspeed is a fine developer. I found it similar to Microphen, but it still has the limits of grain, speed and sharpness that all the other PQ and HQ developers have. It is also a powder.
The OPs asked what liquid developer is most similar to Xtol. The answer is Moersch Eco.