It depends on what you like. I've been vaping for 8 months and have 6 eco C upgrade regulars and passthrough both 650 and 1000mah. I never adjusted I guess because I still liked smoking a few a day. I picked up an Njoy King Bold a couple of weeks ago and wow! I didn't even think about smoking with it but its just too pricey. So I got my two eroll kits four days ago and used my egos a couple of times the first two days but put them all in a drawer today... along with all the 510 stuff I have which still never gave me that "just had a smoke" feel but were more portable and public-friendly. Compared to the eroll, they're very heavy so I've lightened to load. Just eroll for me and don't think about smoking. I smoked for 58 years and was so accustomed to the feel in my hand, taking a smoke from the pack, putting it out, etc and sucking on a drip tip with a bulky thing in my hand just didn't do it for me. The eroll does. I chain vaped that ego trying to get the same satifaction my body and brain was used to. Now I don't chain vape. It hits the same as the ego upgrade unregulated (3.7) and uses the same atomizer. I don't know what they've done to get such a punch in such a little battery. I just wish I had listened to the folks who recommended it to me a way back... but better late than never.
PS: I do use a stronger flavor juice because it uses a clearo and I was used to more flavor. I used cartos with the egos. I also upped my nic because I'm not chain vaping now which is going to save me a lot of money. Aaaand, clearos are way cheap, attys last a long time depending on the juice... savings there too.... much less than the cartos I was using and the batteries themselves cost less. The PCC, if bought in a kit is economical too. Geeez... I'm not connected to eroll sales at all.

Just happy I found it.
The only thing that ego has over the eroll is the plumes. Lots of VG with the ego is going to you more of that than the eroll, at least the kind of draws I take, but there's still plenty of exhale vapor... more than smoking for sure. I thought I liked all those clouds of vapor but have found I don't miss them at all. Looking back, they were more a novelty than anything.
Edit: Ugh, I just saw you weren't talking about the Njoy King. I've never used the Njoy rechargable but from what I've seen, the eroll is head and shoulders above that in vape quality... more like Njoy King but better depending on your juice and lasts all day with the PCC.