1. I have the Line 6 Spider IV HD150 with 4x12 cab.
2. One thing that frustrates me using the effects of the amp, is you can not use another effect on the same knob when you are already using one of the other effects on the same knob. You don't have the choice in combining them in other words. Also I would love to have a looper longer than 14 seconds.
3. It is not as important for me to have presets beyond four channels.
4. It is extremely important for the larger spiders to have an LCD display IMHO.
5. It may be acceptable to reserve deeper parameters to third party devices, but it would be more beneficial to have it where the user can control all of those features from within the amp. (for non-techies)
6. I prefer a front UI but it really does not matter to me. I think the larger amps need to have a front UI so you don't need a ladder to adjust the settings in case you decided to make a full stack out of the unit.
7. The best looking amp on the market without question is the Spider IV amp in my opinion. I get a lot of compliments from friends on the visual appearance of the amp.
8. The first thing I think of is "a do it all amp that sounds amazing." I would buy a Spider V amp when it is released without question. I paid $700 for the head and cabinet and would not hesitate to pay $1,000 + for an updated model with more effects and features.