performance of lvarchar

We have a varchar(255) field which is not used for querying purpose. The field is just selected for display. The length is turning out to be insufficient. Application developers feel that 1024 should be enuf. Since I don't want char(1024) because of space wastage, I am inclining towards lvarchar. In our version 9.21.UC4, that would mean a max string of 2048 can be stored. How is the performance of lvarchar? I don't know how is lvarchar stored in a table. The table is a heavy hit (both insert and select) table and I am not sure how much the performance will degrade when we move from varchar(255) to lvarchar. Any experience with this field. BTW some Oracle experienced developers at my place are smirking that informix varchar supports only upto 255 char. I too think this is an annoying limitation. Ravi