The adjustable zoom on the LX3 would be useful on suspended bait fish. The VX1 with the bottom zoom would be more than enough for Lake Trout. If it were me I would get the VX1 and use the extra coin for gear. Now If I was going to consider upgrading from the VX1 I would go all in and get the LX5, adjustable zoom and standard dual beam transducer, which is the best of both worlds for all species.