td05, Td06sl2 and H 20g are 47lb per min td05 18g is 43lb per min. The td05 will spool faster but fall of quicker up top being a smaller turbine housing and wheel and will make less power because of this. Just based on boost alone my td04 would taper to 9 psi, my vf52 would taper to 16psi and my td06sl2 20g 8cm will taper to around 20-22 psi. Even my friends 2.5xtr tapers to around 22-24 psi at redline and its a 49lb turbo. The only turbo that will not taper on our 2.5 liters would be 35r territory in the 55lb and up size. My 20g will hit peak 26psi at 4200rpm and when it shifts at 6300rpm it will have tapered to 20-22 psi depending on the gear but believe you cant even feel it taper as it pulls hard to redline. The larger the housing/wheel the more power it will make but will also shorten the power band by spooling later. The td06 will alway make more power then a td05 but it all depends on what you want the turbo for? I drag my car and rarely beat on it around town and find the td06sl2 to be perfect for that. When i am at the track there is never any lag because i am launching in boost and after it launches the rpm is never below 4200 rpm so it is never out of peak boost.
Here is a good comparison of different turbos http://forums.nasioc.com/forums/showthread.php?t=2559017
Here is a good comparison of different turbos http://forums.nasioc.com/forums/showthread.php?t=2559017